Buggy title bar appears in focus mode after long uptime

[PennRobotics]

Windows Terminal version

1.19.2682.0

Windows build number

10.0.19045.3570

Other Software

No response

Steps to reproduce

1. Set up focus mode as the default for all sessions.
2. Run Windows a reasonably long time without restarting
3. Open a new terminal
4. Sometimes (even now, not always) a title bar will appear

Expected Behavior

No title bar in focus mode

Actual Behavior

Title bar appears in focus mode—sporadically and after a long system uptime and resource usage.

The window cannot be dragged using the title bar, but the buttons (min/max/close) still function as expected. There are no tabs or text in the title bar.

Currently, I'm at 3:23:14:42 uptime after waking, vmmem was at 5.5 GB. (After the first crash, it is at 3.8 GB.) If I run a handful of wasteful tasks to run up resource usage (e.g. multiple ripgreps in Win command prompt and WSL at the same time) I can exceed 6 GB usage but this doesn't cause the title bar to appear in newly opened terminal processes.

This seems to be a problem independent of profile and other processes. I can run wt cmd and a title bar is there, then wt ubuntu and it's there, then wt powershell and it's no longer there, even though the other terminal processes are still open.

Restarting Windows will restore the expected behavior: no title bar

(update: unrelated to PID stored in a 16-bit variable; problem exists while all PIDs are under 23000)

[PennRobotics]

Related: #16211

[PennRobotics]

Sometimes, the "not last" Settings menus will not crash.

[zadjii-msft]

The settings thing is definitely separate bug from the focus mode ones. I'll try and narrow this thread down to just the focus mode ones.

I bet it's a pretty similar root cause though. Some sort of leftover state from the refrigeration/reheat.

[sim590]

I think that this happened after build 1.17.11461.0 and before 1.18.2681.0. I did try the following packages:

State	Package
good	Microsoft.WindowsTerminal_1.17.11461.0_8wekyb3d8bbwe.msixbundle
bad	Microsoft.WindowsTerminal_1.18.2681.0_8wekyb3d8bbwe.msixbundle

I can reproduce this issue by simply opening a couple of instances of the terminal repeatedly. At some point, I get this bugged title bar:

It took me 4-5 tries here.

But on 1.17.11461.0, it never does that.

I would like to note also that I found a that version 1.18.2681.0 was significantly slower on startup compared to 1.17.11461.0 for some reason.

[zadjii-msft]

That would track with my refrigeration assumption. That was introduced in #15424