[iOS] App freezes with 100% CPU usage when a touchable is used inside a nested stack's `headerLeft` (repro provided + reproduces consistently)

[SimpleCreations]

Description

When the app has a specific combination of bottom tabs, nested stack navigators and headerLeft, it can freeze and stop responding to input. The Xcode debugger shows 100% CPU usage while the app is frozen.

This only reproduces on iOS < 26. I've verified the issue on simulators with iOS 18.6 and 17.5.

Screen.Recording.2026-04-24.at.23.59.32.mov

Steps to reproduce

1. Run the code below. ⚠️ Important: run on iOS < 26 to reproduce the bug.
2. Press "Navigate to Form screen", then "Navigate to Detail screen", then "Go back".
3. Repeat step 2 a few times for good measure. Often doing it once is enough.
4. Press on "TabB".
5. Observe that the app no longer responds to touches. Observe high CPU usage and an eventual crash.

import { useLayoutEffect } from 'react';
import { Button, ScrollView, Text, TouchableOpacity } from 'react-native';
import { NavigationContainer } from '@react-navigation/native';
import { createNativeStackNavigator } from '@react-navigation/native-stack';
import { createBottomTabNavigator } from '@react-navigation/bottom-tabs';

const MainScreen = ({ navigation }) => (
  <Button
    title="Navigate to Form screen"
    onPress={() => navigation.navigate('Form')}
  />
);

const ScrollInnerScreen = () => (
  <ScrollView>
    {Array.from({ length: 50 }, (_, i) => (
      <Text key={i}>{i}</Text>
    ))}
  </ScrollView>
);

const nestedStack = createNativeStackNavigator();

const ScrollScreen = () => (
  <nestedStack.Navigator>
    <nestedStack.Screen name="ScrollContent" component={ScrollInnerScreen} />
  </nestedStack.Navigator>
);

const bottomTabs = createBottomTabNavigator();

const BottomTabsScreen = () => (
  <bottomTabs.Navigator initialRouteName="TabA">
    <bottomTabs.Screen name="TabA" component={MainScreen} />
    <bottomTabs.Screen name="TabB" component={ScrollScreen} />
  </bottomTabs.Navigator>
);

const DetailOverviewScreen = ({ navigation }) => {
  // Does not reproduce if I remove this
  useLayoutEffect(() => {
    navigation.setOptions({ headerLeft: () => <TouchableOpacity /> });
  }, [navigation]);

  return <Button title="Go back" onPress={() => navigation.goBack()} />;
};

const detailStack = createNativeStackNavigator();

const DetailScreen = () => (
  <detailStack.Navigator>
    <detailStack.Screen
      name="DetailOverview"
      component={DetailOverviewScreen}
    />
  </detailStack.Navigator>
);

const FormScreen = ({ navigation }) => (
  <Button
    title="Navigate to Detail screen"
    onPress={() => navigation.replace('Detail')}
  />
);

const rootStack = createNativeStackNavigator();

const App = () => (
  <NavigationContainer>
    <rootStack.Navigator>
      <rootStack.Screen name="Main" component={BottomTabsScreen} />
      <rootStack.Screen name="Detail" component={DetailScreen} />
      <rootStack.Screen name="Form" component={FormScreen} />
    </rootStack.Navigator>
  </NavigationContainer>
);

export default App;

  "dependencies": {
    "@react-navigation/bottom-tabs": "7.15.10",
    "@react-navigation/native": "7.2.2",
    "@react-navigation/native-stack": "7.14.12",
    "react": "19.2.3",
    "react-native": "0.85.2",
    "react-native-safe-area-context": "5.7.0",
    "react-native-screens": "4.24.0"
  }

I couldn't manage to reduce the repro further (e.g. remove bottom tabs) — seems that everything in the above code contributes to the freeze in some way.

Snack or a link to a repository

https://github.com/SimpleCreations/SEE_REPRO_ABOVE_sorry_bot

Screens version

4.24.0

React Native version

0.85.2

Platforms

iOS

JavaScript runtime

Hermes

Workflow

React Native (without Expo)

Architecture

Fabric (New Architecture)

Build type

Debug mode

Device

iOS simulator

Device model

iOS 18.6 simulator

Acknowledgements

Yes

[kmichalikk]

Hi @SimpleCreations
I am not able to reproduce on my mac. I have a new community/cli app, only react-navigation and screens installed and copy/pasted your repro. I'm running it on 18.6 simulator, iPhone 16 Pro.

Simulator.Screen.Recording.-.iPhone.16.Pro.-.2026-04-27.at.14.48.49.mov

Do I need an old iPhone sim for this? Does this work for you on newer iPhones?

[SimpleCreations]

Hi @kmichalikk, thank you for looking into this, I appreciate it very much!

I was able to reproduce the issue also on the iPhone 16 Pro (18.6) simulator.

I've made a video reproducing the issue from scratch, including the initial setup of the repro project. Please take a look and let me know if this helps:
https://drive.google.com/file/d/1FIOcf5w9M9fmnNmcDZlhTgzoprmZeTbX/view

[SimpleCreations]

@kmichalikk hi! I've recorded a trace via the Xcode profiler hoping this would help find the cause of the issue. It seems that the main thread is stuck doing accessibility hit tests. I've attached the trace file below. Do you have any thoughts on this?

https://drive.google.com/file/d/1jy5eE3RMuk48wgMEkTOUvXk3xiL5f_gt/view

Here's a snippet from the profile during the freeze:

16.62 s  100,0%	0 s	 RnScreensHeaderTitleAlignBugRepro (38125)
10.01 s  60,3%	0 s	  Main Thread (0x5a10c)
10.01 s  60,3%	0 s	   start
10.01 s  60,3%	0 s	    start_sim
10.01 s  60,3%	0 s	     __debug_main_executable_dylib_entry_point
10.01 s  60,3%	0 s	      static AppDelegate.$main()
10.01 s  60,3%	0 s	       static UIApplicationDelegate.main()
10.01 s  60,3%	0 s	        0x184873644 (UIKitCore +0x946a7) <8D3F22BC-9DEC-3601-B822-2B88624BE742>
10.01 s  60,3%	0 s	         UIApplicationMain
10.01 s  60,3%	0 s	          -[UIApplication _run]
10.01 s  60,3%	0 s	           GSEventRunModal
10.01 s  60,3%	0 s	            CFRunLoopRunSpecific
10.01 s  60,3%	0 s	             __CFRunLoopRun
10.01 s  60,3%	0 s	              __CFRunLoopDoSource1
10.01 s  60,3%	0 s	               __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE1_PERFORM_FUNCTION__
10.01 s  60,3%	0 s	                mshMIGPerform
10.01 s  60,3%	0 s	                 _XCopyElementAtPosition
10.01 s  60,3%	0 s	                  _AXXMIGCopyElementAtPosition
10.01 s  60,3%	0 s	                   _handleNonMainThreadCallback
10.01 s  60,3%	0 s	                    ___AXXMIGCopyElementAtPosition_block_invoke
10.01 s  60,3%	0 s	                     _copyElementAtPositionCallback
10.01 s  60,3%	0 s	                      -[UIWindowAccessibility _accessibilityHitTest:withEvent:]
10.01 s  60,3%	0 s	                       -[UIViewAccessibility _accessibilityHitTest:withEvent:]
10.01 s  60,3%	0 s	                        -[UIViewAccessibility __accessibilityHitTest:withEvent:]
10.01 s  60,3%	0 s	                         -[UIViewAccessibility _accessibilityHitTest:withEvent:]
10.01 s  60,3%	0 s	                          -[UIViewAccessibility __accessibilityHitTest:withEvent:]
10.01 s  60,3%	0 s	                           -[UIViewAccessibility _accessibilityHitTest:withEvent:]
10.01 s  60,3%	0 s	                            -[UIViewAccessibility __accessibilityHitTest:withEvent:]
10.01 s  60,3%	0 s	                             -[UIViewAccessibility _accessibilityHitTest:withEvent:]
10.01 s  60,3%	0 s	                              -[UIViewAccessibility __accessibilityHitTest:withEvent:]
10.01 s  60,3%	0 s	                               -[UIViewAccessibility _accessibilityHitTest:withEvent:]
10.01 s  60,3%	0 s	                                -[UIViewAccessibility __accessibilityHitTest:withEvent:]
10.01 s  60,3%	0 s	                                 -[UIViewAccessibility _accessibilityHitTest:withEvent:]
10.01 s  60,3%	0 s	                                  -[UIViewAccessibility __accessibilityHitTest:withEvent:]
10.01 s  60,3%	0 s	                                   -[UIViewAccessibility _accessibilityHitTest:withEvent:]
10.01 s  60,3%	0 s	                                    -[UIViewAccessibility __accessibilityHitTest:withEvent:]
10.01 s  60,3%	0 s	                                     -[UIViewAccessibility _accessibilityHitTest:withEvent:]
10.01 s  60,3%	0 s	                                      -[UIViewAccessibility __accessibilityHitTest:withEvent:]
10.01 s  60,3%	0 s	                                       -[UIViewAccessibility _accessibilityHitTest:withEvent:]
10.01 s  60,3%	0 s	                                        -[UIViewAccessibility __accessibilityHitTest:withEvent:]
10.01 s  60,3%	0 s	                                         -[UIViewAccessibility _accessibilityHitTest:withEvent:]
10.01 s  60,3%	0 s	                                          -[UIViewAccessibility __accessibilityHitTest:withEvent:]
10.01 s  60,3%	0 s	                                           -[UIViewAccessibility _accessibilityHitTest:withEvent:]
10.01 s  60,3%	0 s	                                            -[UIViewAccessibility __accessibilityHitTest:withEvent:]
10.01 s  60,3%	0 s	                                             -[UIViewAccessibility _accessibilityHitTest:withEvent:]
10.01 s  60,3%	0 s	                                              -[UIViewAccessibility __accessibilityHitTest:withEvent:]
10.01 s  60,3%	0 s	                                               -[UIViewAccessibility _accessibilityHitTest:withEvent:]
10.01 s  60,3%	0 s	                                                -[UIViewAccessibility __accessibilityHitTest:withEvent:]
10.01 s  60,3%	0 s	                                                 -[UIViewAccessibility _accessibilityHitTest:withEvent:]
10.01 s  60,3%	0 s	                                                  -[UIViewAccessibility __accessibilityHitTest:withEvent:]
10.01 s  60,3%	0 s	                                                   -[UIViewAccessibility _accessibilityHitTest:withEvent:]
10.01 s  60,3%	0 s	                                                    -[UIViewAccessibility __accessibilityHitTest:withEvent:]
10.01 s  60,3%	0 s	                                                     -[UIViewAccessibility _accessibilityHitTest:withEvent:]
10.01 s  60,3%	0 s	                                                      -[UIViewAccessibility __accessibilityHitTest:withEvent:]
10.01 s  60,3%	0 s	                                                       -[UIViewAccessibility _accessibilityHitTest:withEvent:]
10.01 s  60,3%	0 s	                                                        -[UIViewAccessibility __accessibilityHitTest:withEvent:]
10.01 s  60,3%	0 s	                                                         -[UIViewAccessibility _accessibilityHitTest:withEvent:]
10.01 s  60,3%	0 s	                                                          -[UIViewAccessibility __accessibilityHitTest:withEvent:]
10.01 s  60,3%	0 s	                                                           -[UIViewAccessibility _accessibilityHitTest:withEvent:]
10.01 s  60,3%	0 s	                                                            -[UIViewAccessibility __accessibilityHitTest:withEvent:]
10.01 s  60,3%	0 s	                                                             -[UIViewAccessibility _accessibilityHitTest:withEvent:]
10.01 s  60,3%	0 s	                                                              -[UIViewAccessibility __accessibilityHitTest:withEvent:]
10.01 s  60,3%	0 s	                                                               -[UIViewAccessibility _accessibilityHitTest:withEvent:]
10.01 s  60,3%	0 s	                                                                -[UIViewAccessibility __accessibilityHitTest:withEvent:]
10.01 s  60,3%	0 s	                                                                 -[UIViewAccessibility _accessibilityHitTest:withEvent:]
10.01 s  60,3%	0 s	                                                                  -[NSObjectAccessibility accessibilityElementCount]
10.01 s  60,3%	0 s	                                                                   -[NSObject(AXPrivCategory) _accessibilityElements]
10.01 s  60,3%	0 s	                                                                    -[UINavigationBarAccessibility accessibilityElements]
10.01 s  60,3%	0 s	                                                                     -[UINavigationBarAccessibility _accessibilityFetchCachedNavBarElements]
10.01 s  60,3%	0 s	                                                                      -[UIView(UIAccessibilityPrivate) _accessibleSubviews:]
10.01 s  60,3%	0 s	                                                                       -[UIView(UIAccessibilityElementTraversal) _accessibilityViewChildrenWithOptions:]
10.01 s  60,3%	0 s	                                                                        +[UIView(UIAccessibilityElementTraversal) _accessibilityElementsAndContainersDescendingFromViews:options:sorted:]
10.01 s  60,3%	0 s	                                                                         -[NSObject(UIAccessibilityElementTraversal) _addAccessibilityElementsAndOrderedContainersWithOptions:toCollection:]
10.01 s  60,3%	0 s	                                                                          -[UIView(UIAccessibilityElementTraversal) _accessibilityShouldBeProcessed:]
10.01 s  60,3%	0 s	                                                                           -[NSObject(AXPrivCategory) _accessibilityAncestorIsKindOf:]
9.27 s  55,8%	117.00 ms	                                                                            -[NSObject(AXPrivCategory) _accessibilityFindAncestor:startWithSelf:findTopmostAncestor:]
4.44 s  26,7%	222.00 ms	                                                                             -[UIViewAccessibility accessibilityContainer]
1.52 s   9,2%	188.00 ms	                                                                             objc_autoreleaseReturnValue
806.00 ms   4,9%	57.00 ms	                                                                             objc_claimAutoreleasedReturnValue
488.00 ms   2,9%	488.00 ms	                                                                             objc_opt_isKindOfClass
339.00 ms   2,0%	339.00 ms	                                                                             objc_retainAutoreleasedReturnValue
299.00 ms   1,8%	299.00 ms	                                                                             objc_msgSend
178.00 ms   1,1%	178.00 ms	                                                                             objc_msgSendSuper2
152.00 ms   0,9%	152.00 ms	                                                                             objc_retain
122.00 ms   0,7%	122.00 ms	                                                                             objc_storeStrong
114.00 ms   0,7%	114.00 ms	                                                                             DYLD-STUB$$pthread_setspecific
111.00 ms   0,7%	111.00 ms	                                                                             DYLD-STUB$$objc_retainAutoreleasedReturnValue
78.00 ms   0,5%	78.00 ms	                                                                             DYLD-STUB$$pthread_getspecific
73.00 ms   0,4%	73.00 ms	                                                                             __59-[NSObject(AXPrivCategory) _accessibilityAncestorIsKindOf:]_block_invoke
57.00 ms   0,3%	57.00 ms	                                                                             objc_msgSend$superview
54.00 ms   0,3%	54.00 ms	                                                                             -[CALayer unsafeUnretainedDelegate]
50.00 ms   0,3%	50.00 ms	                                                                             -[NSObject(UIAccessibility) accessibilityContainer]
47.00 ms   0,3%	47.00 ms	                                                                             DYLD-STUB$$objc_storeStrong
42.00 ms   0,3%	42.00 ms	                                                                             DYLD-STUB$$objc_opt_isKindOfClass
40.00 ms   0,2%	40.00 ms	                                                                             objc_release
37.00 ms   0,2%	37.00 ms	                                                                             DYLD-STUB$$objc_msgSendSuper2
24.00 ms   0,1%	24.00 ms	                                                                             -[UIView(UIKitManual) superview]
21.00 ms   0,1%	21.00 ms	                                                                             objc_msgSend$unsafeUnretainedDelegate
21.00 ms   0,1%	21.00 ms	                                                                             -[UIAccessibilityContainerReferenceHolder referencedContainer]
20.00 ms   0,1%	20.00 ms	                                                                             DYLD-STUB$$objc_release
15.00 ms   0,1%	15.00 ms	                                                                             DYLD-STUB$$objc_retain
187.00 ms   1,1%	187.00 ms	                                                                            objc_autoreleaseReturnValue
151.00 ms   0,9%	151.00 ms	                                                                            objc_release_x22
102.00 ms   0,6%	102.00 ms	                                                                            DYLD-STUB$$objc_autoreleaseReturnValue
81.00 ms   0,5%	81.00 ms	                                                                            objc_msgSend
76.00 ms   0,5%	76.00 ms	                                                                            objc_msgSend$accessibilityContainer
72.00 ms   0,4%	72.00 ms	                                                                            objc_claimAutoreleasedReturnValue
43.00 ms   0,3%	43.00 ms	                                                                            DYLD-STUB$$objc_claimAutoreleasedReturnValue
33.00 ms   0,2%	33.00 ms	                                                                            DYLD-STUB$$objc_release_x22

[kmichalikk]

As a rule, we're not following any links outside of GH. You can provide a repo with your setup, with separate commits for your changes so I can review them, create a recording that is within GH limits or generate a transcription / steps and paste them here. Could you also paste more information about your system and Xcode version you're using?