temp/humidity sensor in the car going faulty isnt uncommonI have been very frustrated by this same problem in my 2021 Model Y. The car can make plenty of cold air, and it can make plenty of hot air, but it has a very difficult time regulating the temperature. One day 68 is barely cool, and the next day 76 is freezing cold! It really seems to me the car is having problems measuring the cabin temperature. I have used multiple thermometers and the temp is all over the place.
one way it manifest itself is for me the car failing to activate Climate Keep, or remotely send climate instructions, most often when car is at extreme temperatures i.e. in extremes of summer or winter.