2012 Chevrolet Captiva Sport can’t control heat with switches

Heat gets stuck blowing cold air and then it will switch to defrost and blow cold. Can’t control with switches.

Bad blend door actuator most likely. Common problem.

I think we’ve replace two actuators and a sensor. Had the computer synched at the dealer. It will work for a bit but then gets all crazy. It’s my son’s car so he has all the repair papers. It’s very frustrating. I’ve seen a couple of other posts with the same problem but never a definite solution given that works in the long term.