I have a fix for it with my communication with a Valve developer. ONLY DO THIS IF YOUR COMFORTABLE WITH EDITING FILES IN DESKTOP MODE/CONSOLE. You can also just wait for the update which i was told will be out ASAP.

Do the following:

Open a terminal prompt (Called Konsole in desktop mode)

Make sure you setup a sudo password for your deck user by running “passwd” (without quotes, applies to each command i give after this). If you did this already, skip this step.

Make sure read only is disabled by running: “sudo steamos-readonly disable”. It will ask you to enter your password. You can enable this again when completed by just replacing disable with enable.

Then do:

sudo nano +45 /usr/share/wireplumber/main.lua.d/60-alsa-acp5x-config.lua

Remove the entire line 45. The command i gave you should have you on the line. It should look like “[“api.alsa.period-size”] = 256,”

Save it by CTRL + O. Then exit nano via CTRL + X. Reboot by typing sudo steamos-reboot.

Test the mic. Should work if done correctly.

Again, i am not held responsible if you do this incorrectly. If you are not comfortable doing this, wait for the official update for the fix.