My problem was inability to hear calls using phone in normal mode. (Speaker phone and Bluetooth calls worked fine.) I hoped the Android 12 update would fix it, but it didn't. I completed a hard reset, and that didn't fix it either.
My phone was under warranty, so I made use of that. They shipped me a refurbished unit (and I shipped mine back.) THAT FIXED IT!
I think it must have been some kind of hardware issue.