I wanted to update my post for anyone else having a problem activating their Apple Watch with their new xfinity mobile plan. Our phones were BYOD and not purchased from xfinity. I did a complete factory reset on the watches (not the phones) to remove any carrier information. We set them up as new phones and did not use the restore feature. The next step is the crucial step that changed everything. The instructions we found stated to remain connected to wifi. After spending a few hours reading different posts on the forum, we found one that recommended TURNING OFF WIFI. We turned off Wifi on both the phone and the watch and BINGO the activation finally worked.
Hope this helps others!
I'm hoping @ComcastChrisL or someone else can offer some help since I've seen so many people say he has! My husband I just activated our mobile service with Xfinity yesterday. We then went to activate our two Apple watches (both series 4 GPS+Cellular). We performed a reset on both and set both watched up as new watches to make sure all previous cellular plans were wiped from them. We got to the last step of cell activation and were met with a screen that said "Uh-oh. Something went wrong. We ran into a problem during the activation process and your information was not saved. Please restart activation. If this problem persists, contact customer service at (844) 963-0125." We turned off the watches and phones and re-attempted activation numerous times last night and this morning, but receive the same message. I called cutomer support and the woman I spoke with clearly had no clue what she was talking about and even told me that Xfinity was not accepting BYOD apple watches.
Can someone help?