Hello. Bought a Nike Series 5 New.
After being on the phone with my carrier for 3 hrs on & off. I literally figured it out on my own.
For XR w/ SERIES 5
Once your watch is back at the...sit the devices side by side screen:
All apps closed including WATCH APP
Slide down CONTROL CENTER & SHUT OFF CELLULAR DATA with WIFI ON
Open WATCH APP and go through the steps to update manually, which is in fine print on the UPDATE NOW screen.
PAIR by inputting the number on the WATCH to the WATCH APP prompt.
That should do it!
Currently waiting 25mins for software update.
HOPE THIS WORKS