This thread looks to be several months old, but I’m encountering the same type of issue. I’ve recently installed several software updates, so it’s unclear which of them might have broken the watch app. I’m running iOS10 on an iPhone 6+ ahd have an original Apple watch running WatchOS3. I just recently updated to the latest SmartThings mobile app. (Sept 2016)
When I went to the SmartThings app in the dock on the watch it initially displayed the message “Manage Apple Watch from My Account in SmartThings”. Doing that, I found the four sliders to activate the scenes were all selected OFF (I had them all ON in the previous version). I turned them back ON and hit Done, Returning to the selection screen showed them all OFF again. I tried again about a day later and found that the watch app had mysteriously started “working” in that the manage message was gone. Now it displayed 2/4 scenes, ironically the 2 that I would probably never use. Still the same behavior from the mobile app in that any changes weren’t retained after hitting Done.
Is this a known issue, and is there a solution?