Space bar activates previously clicked UI element (widget) due to FocusPolicy

Operating System Info

Ubuntu 20.04

Other OS

No response

OBS Studio Version

27.1.3

OBS Studio Version (Other)

No response

OBS Studio Log URL

n/a

OBS Studio Crash Log URL

No response

Expected Behavior

I expect that hitting space bar will trigger the hot key for space bar.

Current Behavior

Space bar is being intercepted by some sort of accessibility feature, and is treated as a click on the last button clicked. So that means if you start recording and hit the space bar, recording stops. For other buttons, like the crossfade button, it pops up a contextual window. So maybe it's acting like a right click. Not sure.

This occurs on both gdm3 and lightdm.

This bug also appears to exist on Windows:
https://obsproject.com/forum/threads/can-i-stop-spacebar-from-acting-as-a-hotkey.66796/page-2#post-546420

Steps to Reproduce

1. Set the space bar to be the hotkey for something useful, like a cross-dissolve.
2. Click the "Start recording" button.
3. Press the space bar. Observe that the recording stopped.

Anything else we should know?

This definitely does not reproduce on macOS in version 25.x, and I'm 99% sure it doesn't reproduce on macOS in 26.x. So assuming this affects all platforms, this is probably a regression in version 27.x.

Start with the documented reproduction using the Start recording and cross-dissolve controls, and investigate the widget FocusPolicy behavior described in the report. Done means the space-bar hotkey fires after another UI element is clicked instead of activating that element; no source file or test is named in the issue.