Freezes in FaceTime after updating MacBook Pro to Catalina

Support had me do something other than zap the PRAM to stop my laptop from freezing during FaceTIme, especially when I am using AirPods. I was told to hold down two keys along with the Start button while the computer was shut down and to hold this key combo for 20 seconds. Now I cannot remember the combination of keys. Anyone have an idea of what I might have been told to do?