Have you tried unpairing and setting up as new watch already? Or did it reoccur because of iOS 11.1 Beta 4?
I'm too old and lazy to go through stuff like that any more. I just wait for Apple to fix stuff and they usually do. Sometimes it takes weeks, sometimes months to years - but like I said, I'm old and lazy.
It's why I switched to Apple from Microsoft and Google.
I don't have to constantly reflash, reset and rebuild my electronic crap anymore. I only need to be patient and wait. And give Apple all my money.