Your system information

• Steam client version (build number or date): 1769025840
• Distribution (e.g. Ubuntu): Bazzite
• Opted into Steam client beta?: Steam Deck Stable
• Have you checked for system updates?: Yes
• Steam Logs: steam-logs.tar.gz
• GPU: Sapphire nitro+ AMD RX 7800 XT

Please describe your issue in as much detail as possible:

I have a multi-screen setup and wanted to enter desktop mode.
I usually only turn on whichever screen I want to use(1080p@165hz gamescope/desktop mode, 1080p60 tv gamescope mode).
The multi-screen management does properly remember per-monitor scaling options depending on utilised by the gamescope monitor.
I tried to setup apple TV+ via a streaming box, and I had both open wanted to check something on my computer screen and enter desktop mode.
My TV was turned on so gamescope detected that and only displayed content on the TV even if I used the streaming box.
I thought I was facing the old issue from 2-3 years ago that would randomly make big picture gamescope session fail to launch, so I've rebooted the computer 5 times.
By which point I switched the HDMI output to be greeted by the steam game courier service with a gift(summer sale startup screen).
I went to the settings screen, clicked on the display options and couldn't toggle screen mirroring or anything of the sort.

Steps for reproducing this issue:

1. Connect the computer to a monitor(display port).
2. Connect the computer to a TV(HDMI port).
3. Turn both the screens on.
4. Launch the computer.
5. Only one of the screens is utilised, the option which one is the main is non-configurable/the first screen that was connected at setup is assumed to be the main one.