I have experienced a similar issue. In my case, I am running SteamOS on a mini PC that is connected to a 7" touchscreen. Maximum game resolution is showing 1024 x 600 within the settings. While the left-side Steam menu overlay works perfectly fine with my Xbox controller when not in a game, with any game running you can bring up the side menu with the Xbox button, but cannot navigate to any menu item with the controller, an attached keyboard, or the touchscreen input. The only button that works is the Xbox button, which you can be used to close the overlay. Input seems locked to the game that is running.
I have this exact same issue on the Steam Deck when docked and outputting 640x480 to an old TV. Both the Deck's controls and any external controller are locked to the running application. Only the guide button works to open and close the overlay. Removing the Steam Deck from the dock restores control.
just to confirm - is everyone here experiencing this issue while running in Game Mode, or does this also happen in desktop mode on Steam Deck if you launch Steam into Big Picture Mode from KDE?
For me, this happens in Big Picture mode. Any game I launch from there works fine in game, and the game menus work, but if I use the Xbox controller to open the left side Steam menu, I cannot select anything at all, there is zero input from the controller. All I can do is close it again and use the in game options.
For me, this happens in Big Picture mode
Sorry, do you mean in game mode (i.e. the default session that SteamOS boots into) or do you mean when you press "Switch to Desktop Mode" and then launch Steam in big picture mode (i.e. the same UI as Game Mode, but running on top of desktop mode).
I reproduced a similar issue in the game mode session and I have a fix for it, but if this issue also happens in desktop mode with the same big picture mode UI, then there is some underlying Steam issue as well.
Ah, sorry. The default mode, the console experience. I have not used desktop mode.
Cool, I think I accidentally fixed it as a part of https://github.com/ValveSoftware/gamescope/pull/2228 then, and this was never a Steam issue but rather a gamescope issue.
The latest update in beta version have resolved the issue for me. Having separate resolutions for the Steam client and games allows me to run Steam Gaming Mode at a higher resolution while launching games at a lower resolution, which works well. However, it is worth noting that some games may appear very small when using integer scaling at lower resolutions.
When setting the native resolution of the main display to 1152x864 or lower and launching a game, the side menus can be summoned but are unresponsive using the controller. The focus seems to stay on the game window instead of the steam menu. 1400x1050 works fine, while 720x400 has the same bug, which tells me it's not an issue with the aspect ratio.
Steps for reproducing this issue: