So, the number share profile has been deactivated.
I've asked one of the agents managing your fault to go in and apply the number share add-on.
You should receive an SMS confirming that there's been a change on the account.
Give it another 10-15 minutes and attempt to pair again.
Issue is 100% resolved on my end and have been able to enable mobile data on my watch.
No idea what they had to do to fix the problem but I'm glad it's done now!
Didn't have to do anything but going into the watch up and click on 'mobile' to get it going thank goodness. I think if I'd had to reset the watch again I would have lost it!
Hey @Dan_C , I'm having this exact issue with a new series 5 Apple Watch after previously having a series 3. What do I need to do to fix it? I tried to PM you via a previous link you've posted, but it just takes me to a general page. Thanks.