I updated to iOS 11 today. Right after the update, I noticed I was not seeing the AT&T call letters by the signal bars. I kept seeing the following repeated sequence every minute or so: Signal Bars with "LTE" Just Signal Bars No Service When it would sequence to just signal bars or no service, I had no internet I checked my AT&T account and there are no issues, it knows I have the card inserted in the iPad Pro. I looked in settings, the iPad knows I have an AT&T Sim Card inserted, but the Carrier tab keeps disappearing during the sequence of events above and then reappears. I tried resetting network settings, pulling the Sim Card - Shut down and reinsert, and restoring the iPad to new. None of the efforts above resolved the issue. I inserted the Sim Card into my iPad Mini and it worked fine. Reinserted the Sim Card back into the iPad Pro and still having the same problem. I never had this issue until after the first boot up to iOS 11. I have an appointment at the Apple Store tomorrow to hopefully resolve the issue.