I received my iPhone pro max today. I set my phone from iTunes backup. Before activating my phone with my service provider, I upgraded my phone to new iOS 15. I wasn’t able to activate my phone with the service provide. They had to activate over the phone. Now my phone and text are working. But, my data isn’t working. Att is pointing finger towards manufacturer and saying they have lot of complaints with data with new phone and also iOS 15. I tried resetting network options, full factory reset, erase and restore, removed the SIM and put it back in and also multiple restarts. Nothing helped. At this point att says they have raised this issue to back office and also manufacturer. Is anyone else facing this issue and we’re able to resolve?