Ultra 2 watch would not send/receive calls / data functions would not work when not in close proximity to iPhone on T-Mobile network

I have a 2 month old Ultra 2 watch that I was trying to get cellular functions to work while not tethered to my phone. I’m a T-Mobile customer and also have an iPhone 15 Pro Max on the same account. After over a month of unpairing and re-pairing work with my provider and engaging apple support, I submitted an apple care claim that was processed by Apple for a new ultra 2 watch. T-Mobile was still unable to get cellular to properly function. Watch and iPhone both reported that cellular was connected, but still unable use apple watch unless they were in close proximity.

I grew very frustrated with provider after they wasted my time troubleshooting the problem. Today Oct 21, 2024, I had them escalated this to their engineering team as I was getting nowhere with their normal support.

Here is what they came back with, I was on a unlimited data plan, so they downgraded my plan to the basic 500GB plan. To my surprise, the change they made on the backend in the plan worked after restarting both devices.

I asked that I need to understand the “why” that the unlimited plan was blocking the full cellular functionality and I would like to go back to my original plan. Will keep everyone posted on progress.