Yep, this is exactly the same issue that I'm having. I updated my watch to 4.1 beta last night to see if it made any difference, but it hasn't.
My friend bought their watch last week and it connected fine and made a few test calls, we both went out today and mine conncected to EE within a few minutes but his didnt anymore. Tried rebooting the watch and it wont connect, toggling airplane mode forces it to connect then it slowly drops signal untill it disconnects. Was in the middle of a park with no wifi spots about so it couldnt be the captive portal issue
So. This is the problem I seem to have:
I can see my watch has mobile data connectivity. It shows on the phone.
I go to check it out and the best thing for me is to switch the phone off.
1. I can make calls without issue
2. I can use SIRI
3. I cannot send text messages.
I spoke to EE, they checked it all out, apparently unassigned and reassigned the e-SIM, still same issue.
I then went to apple store, I showed them I can call and use Siri, no messages (it goes “sending...” and he bar never finishes sending).
They ended up changing my watch, for it to still do the same thing.
There was a guy at the store that also had the same issue.
I don’t know what else to try.
Anybody had the same?