Losting logging context on sync request

[timofej673]

Description

When logging sync requests, I see two warnings that the logging context has been lost.

Steps to reproduce

• Open the Matrix client that will send sync requests (for example, cinny)
• Monitor logs of lost context in Synapse on sync requests

Homeserver

My selfhosted private homeserver

Synapse Version

1.140.0

Installation Method

Docker (matrixdotorg/synapse)

Database

PostgreSQL, single postgresql server, ported from sqlite.
I once restored from a backup when the database was in SQLite format.

Workers

Single process

Platform

Arch Linux
Linux 6.16.8
Core i5-4200M
8GB ram
Run on real hardware, without virtualization

Configuration

No response

Relevant log output

synapse-1  | 2025-10-16 01:24:25,624 - synapse.logging.context - 107 - WARNING - GET-367 - Expected logging context sentinel but found call_later
synapse-1  | 2025-10-16 01:24:25,626 - synapse.logging.context - 107 - WARNING - sentinel - Expected logging context call_later was lost
synapse-1  | 2025-10-16 01:24:25,627 - synapse.access.http.8008 - 521 - INFO - GET-367 - <redacted> - 8008 - {<redacted>} Processed request: 30.007sec/0.001sec (0.007sec, 0.001sec) (0.000sec/0.000sec/0) 177B 200 "GET /_matrix/client/v3/sync?filter=0&timeout=30000&org.matrix.msc4222.use_state_after=true&since=xxx HTTP/1.1" "<redacted>" [0 dbevts]

Anything else that would be useful to know?

This is a regression. This bug isn't present in 1.39.2