keyboard shortcut for main menu randomly stops working

[Luukie13]

Your system information

• Steam client version: 1784778118
• SteamOS version: 3.8.24
• Opted into Steam client beta?: Yes [Yes/No]
• Opted into SteamOS beta?: Yes [Yes/No]
• Have you checked for updates in Settings > System?: Yes [Yes/No]

Please describe your issue in as much detail as possible:

Describe what you expected should happen and what did happen.
When I try to hit the pre-assigned home menu shortcut on keyboard I would expect it to open the home menu.
However seemingly randomly within the same session, with the same apps open, it will stop working and send those inputs through to my browser/discord. Ive tried this with both the default and a bunch of other hotkeys including currently the home key. All to the same result.

Steps for reproducing this issue:

1. Launch into game mode. opening firefox, discord and whatever game you feel like.
2. Use the computer like normal. Occasionally switching between tabs. Playing a game. Anything.
3. At some point the keyboard shortcut will just stop working while the controller one is fine.

[matte-schwartz]

this is likely one of the cases I fixed in ValveSoftware/gamescope#2269, I'll let you know when it's in an OS build for testing later on.