Loss of Cellular data for apps

We have same issue with an iPhone XR and after couple of hours on the phone with T-Mobile and Apple they were unable to resolve. We tried all the troubleshooting steps, sim swaps and even full factory reset/restore to no avail. Unfortunately we don't have line of sight on resolution but reopened a case with Apple. The T-Mobile people we talked to at our local T-Mobile store noted several others have been in over last few days with similar issues that have stumped them. They mentioned one of these individuals even upgraded to a new phone and the problem reoccurred couple days later. I have to wonder if the turn-up of 5g last week could have some relationship- that's the only thing I can think that changed about the time this started to effect us.