Yep, this was it. Works just fine with anything except the rearview camera at the bottom half. That is my default setup, but amazing that I must never have adjusted the temp except when I had the camera there. Thanks, GeekGirls!
You're most welcome! I'm glad I could help.
Wow, observant pickup...kudos, I bow to your Tesla-Fu skills.
+1 Wow.
:redface: Mark it down to spending rather a lot of time in the software industry. Debugging unexpected behaviour is a skill that comes in handy each and every day.