I put Michelin Primacy MXM4 tires on the back. I left the factory 235/45R18 tires on the front because they still had a lot of tread. At highway speed, I started getting traction control warnings (nearly continuous) and the car was dumping out of autopilot. I thought I had gotten myself into a mess. I pulled off the road and - using the service console - I reset the tire size to 19 inch wheels. I drove a little and reset back to 18 inch aero. I don't know if the resetting had anything to do with it, but the car is driving completely fine now. I've completed two long trip and a fair amount of around town driving. I'm guessing the Tesla initially sensed a change in wheel rotation speed and was interpreting it as slip.
Pictures are attached. 245s on the back. Original 235s on the front.
Pictures are attached. 245s on the back. Original 235s on the front.