I'm not able to customize any of my watch faces from the Samsung wear app anymore. Every time I try to customize from the phone, it just shows a loading screen forever. The issue started after the recent update to the watch. It also appears to be impacting only non-samsung phone. My wife has the same watch with S22 and is not facing issues.
Things tried so far -
1. Restarted the watch
2. Hard reset the watch
3. Uninstalled the wear app, plugin app and accessory app on the phone and hard reset the watch.
It depends on the watch face, apparently some are really to complex for the app on the phone to customize and you have to customize the face with the watch
I found slightly newer versions of Samsung Wearable app and Watch5 Plugin in Apkmirror. Sideloading these newer versions seems to have fixed the issue for me. Samsung needs to push these updates to the play store to fix the issue for non-Samsung phones.
Sideloading is HIGHLY NOT RECOMMENDED given recent certificate leak on several major OEM's including Samsung.
I'm not certain if this would work differently on a non-Samsung phone but it appears that it should. When I used this fix, my problem was both; could not customize watch faces from the app. I could only customize them on the watch. And my downloaded watch faces would not show up in the "download" section of the app. Are your downloaded watchfaces showing up in downloaded section of the app. If not, these steps may work for you. Hard to know for certain on a non-Samsung phone.
