Headphone/aux volume jumps to 100 when exiting desktop sleep mode

[tlsctf2]

Your system information

• Steam client version: 1759461205
• SteamOS version: 3.7.17 Build 20251027.1
• 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:

The volume setting for a device connected to the aux port of the Steam Deck jumps to 100 after bringing the device out of sleep mode during use of desktop mode. Often, for someone using headphones that typically require a much lower volume setting, this can result in painfully loud and potentially harmful/damaging sound coming through the device if nothing is done before playing sound through the device.

Steps for reproducing this issue:

1. Connect a device to the aux port.
2. Enter desktop mode.
3. Have the volume set below 100.
4. Put the system into sleep mode from the Application Launcher menu.
5. Exit sleep mode using the power button.
6. Observe, either with ears or (preferably) eyes, that the volume is now set to 100.