Going in this Wednesday for the v155 update as per the OnStar tech support adviser. My truck will not communicate with the wifi. I can connect to my home wifi or iphone hotspot for about two seconds before the truck disconnects. I can't get the traffic updates on the navigation system either. I tried clearing all my personal info from the truck also and now I cannot sign in except as guest only. They can't do the over the air update because the truck cannot communicate with OnStar except for phone calls only. OnStar told me this is a known problem for 2021 GM vehicles. I'll update if I have success.