Your system information

• Steam client version: 1757650573
• SteamOS version: 3.7.15
• Opted into Steam client beta?: [Yes/No] Yes
• Opted into SteamOS beta?: [Yes/No] Yes
• Have you checked for updates in Settings > System?: [Yes/No] Yes

Please describe your issue in as much detail as possible:

Describe what you expected should happen and what did happen.

Essentially this bug seems to be related to playing docked with a resolution different from the Steam Deck resolution.
So, for example, if I play docked to my 4K TV but set the game to 1080p resolution, the Game Recording will properly record the audio but it will only record the upper left part of the screen for the video.
This is a bug that has been here from as early as I remember being able to play docked. I would assume the Game Recording feature tries to get the video as-is instead of trying to down-scale before.

If I play in portable mode it works just fine, game recording works as expected.
I don't know if it's a SteamOS or Steam client issue though as I only see this on the Steam Deck.

Steps for reproducing this issue:

1. Dock to a screen at least 1080p
2. Set the display resolution on Settings > Display from "Default" to "Native"
3. Have Game Recording enabled
4. Open some game
5. Set this game's resolution to at least 1080p
6. Play for a while
7. Close the game and analyze the recording
8. Notice how it the audio has been recorded properly but the video hasn't