Pane position and sizes can be messed up after a restart

[ac10n]

Windows Terminal version

1.23.13503.0

Windows build number

10.0.26200.0

Other Software

No response

Steps to reproduce

I have a terminal, run as administrator, with multiple tabs and the first tab has multiple panes. Sometimes when restarting terminal, my panes get messed up

Expected Behavior

Panes should stay where they were before restarting, ang most of the time they do

Actual Behavior

Sometimes they are messed up. Restarting again keeps the new (wrong) arrangement, so I have to close them and create new panes with the arrangement I want

[ac10n]

Another instance: The solid gray rectangles show the new position of panes, while the yellow lines show the original ones.
Red arrows show how panes moved around. See how 2 panes stayed in their place while all the rest moved around

[zadjii-msft]

hmm there used to be #4430 which was fixed by #5090 years ago

I'm confident that we have a backlog issue for this. Something about the fact that the pane splitting is based on where focus is, and during startup that's not consistent.

Maybe move-focus or moveFocus is what I need to search?

[DHowett]

We probably need to rethink how we serialize panes (both for permanent storage and yeeting into a new window ;P)