watch faces not showing up in phone app or on watch

Thanks for the info there. I still wasn't able to get mine to work, even after a full erasure and setup as new devices. I discovered it was an issue with iCloud Photos and syncing the photos (for watch faces) to my watches. By default, it selected 100 photos from Favorites. I found that if I turned that off, reduced it to 25, or opened the photos app and waited until they all synced that things would work.

Hopefully this helps someone out in the future. I did let Apple know.

Power cycling the watch and phone didn’t fix it in my case.

for me what did was adding a new watch face to my list. When I did that, the rest of my watch face suddenly reappeared and everting showed again.

I'm having the same issue. I've tried numerous times to unpair and repair both restoring from backup and setting up as a new watch. Prior to that I tried power cycling all of the devices and resetting network settings. I am resorting to setting up my iPhone again, which is incredibly frustrating.

This just happened to me after pearing my Apple Watch 6 with my new iPhone 12 pro that was previously paired with an iPhone 11 Pro. It resolved after I power cycled the watch.