Have the same problem. Last few weeks it is almost impossible to sync. Managed to sunc only 1 watchface.
Have tried everything:
* All advice from "Have trouble syncing? Try these steps"
* Turning on and off flight mode
* Launching Samsung watch app on the phone
* Turning on - off and back on again wi-fi
* Turning watches, watches + phone off and on again
* More than a hundred times clicking "Send to watch" button
Every time it says "Sent", but nothing happens on watches.
While an interesting fact: at my profile page on PC or phone it always correctly show my current watchface - so it definitely has connection with watches.
I'm almost desperate working this application well... Weather displaying, weather updating, phone battery status, now - watchface syncing...
Watch app ver. - 22.214.171.124_ios
Phone app ver. - 126.96.36.199
Hardware: Galaxy Watch + iPhone 6