In another forum a user said these things were happening:
Volume is lowered all the way down (to zero)
Tone settings (base/mid/treble) are completely lost (everything is zeroed out)
Auto-Volume control is reset to none
What fixed the issues for my '21 Colorado was to do a Factory Reset on the Infotainment unit. Go here:
Home (Chevy's dark screen with the Android Auto and Audio buttons among others)
-> Settings
-> Return to Factory Settings.
In another forum a member commented that he did this once and it didn't help. But after his comment he tried it again and it resolved the problem for him too. So you might have to do it more than once for some reason.
Here's a video for MyLink. I have a Work Truck edition Colorado so mine's slightly different but the procedure is pretty similar.