Apple Watch 8: No Sim, Cannot connect to cellular plan

I got a new iphone 14 pro, and my apple watch 8, which previously had no issues with my iphone 11, will not connect to the new phone. Did all of the updates, restarts, resets, pair and unpair. Apple support rep sent me a link basically showing me how to pair the watch, which is not working.

Details:

-T Mobil

-Unlimited data

-Watch is 4 days old

-Phone is 1 day old

-Did not disconnect watch from my old phone before giving it to T Mobil

-Watch is paired just fine with my phone, will not connect to cellular data

-It shows the T Mobil 'thanks for your purchase' screen and then just resets, asking me to set up cellular.

So far, nothing is working- any ideas? I am hesitant to go into a T Mobil store if it is something I can fix at home.