Thanks for the reply. It seems my situation is nearly identical to yours. Only difference I see is that I have a pixel 9 pro. So I reset your theory last night and disconnected my Garmin and made a call. No issues with the call. So I guess my temporary solution is to turn off my Garmin Bluetooth. This makes my truck more useful and less frustrating. If I find an alternative, I will be sure to post here. Also, I am amazed/impressed at your trouble shooting to narrow it down this much.
Thanks again.