I too am having the same problem. Will retain stations etc but will not do so on volume, EQ, Fade etc. Scheduled service and spoke with the rep. He stated that he was aware of this issue but GM does not have a fix yet. Prior post said to flash chip so I think I will ask them to do it anyway to see if it fixes it. GM could be six months. I have had this for 5 months now and it is very frustrating.
Also, My fog lights I have to turn on every time instead of just being on unless I shut them off. I would like for them to be on when driving always except in high beam.