I had the same issue with my '21 GT Plus. I have to "sign into the network" each time I start the vehicle; it also affects the streaming channels in SXM 360L.I discovered the weather app isn't working either. Just loads forever then errors out. Not sure if it's related to my "services not activated" bug or not. In my '16 Charger the weather and gas prices were in their own app, but with the new system I'm not sure where those are supposed to show up. Are they in the weather app or tied into the Nav system and displayed there? Without a working system I don't know where to look. Also does anyone think a system reboot might fix some of my problems and how would I do that?
-tap the Notifications bell in the top bar
-tap "Android System: sign into the network"
-the AT&T sales pitch screen will load up
-tap the three dots in the upper right corner
-tap "use this network as-is"
Once I did all that, everything works fine, but again I have to do this EVERY TIME I start my DD. Also, if you accidentally tap something else and exit the AT&T screen any time before the last step, you're out of luck as there's no way to go back until you restart the system and the notification comes back. I found this by trial-and-error; there's nothing in the docs that tell you what to do, and I can't find any way to have the system use the built in network by default and stay signed in.