[Stable 3.7] Degraded audio quality on Internal Microphone / P3 Headset audio sink

[mario-aleo]

Your system information

• Steam client version: 1748301070
• SteamOS version: 3.7.8
• Opted into Steam client beta?: No
• Opted into SteamOS beta?: No
• Have you checked for updates in Settings > System?: Yes

Please describe your issue in as much detail as possible:

Ever since the launch of 3.7, on my Steam Deck LCD, whenever I open two applications on Gaming mode, for example: Discord and New World (steam game with default proton), I experience degraded sound quality on both applications until one of those applications have been closed.

Steps for reproducing this issue:

1. Using the default audio sink (with or without a P3 headset).
2. On gaming mode, open an application (example: Discord)
3. Still on gaming mode, open a second application (example: Overwatch 2)
4. You should experience a degraded audio quality on both applications.
5. Extra: without a headset, if one of the applications is Discord, it will capture the Steam Deck rumbling as input audio.