I tried using the Strava app for Galaxy Watch (Tizen) a couple of times now. Twice with a bicycle ride, once with a run.
The first ride was about 12 km and tracked just fine. It synched with my Strava profile perfectly. The second ride that I tracked did not sync. And today I did a 8 km run and that too did not sync. So the three activities all show in the history page of the app, I can manually try to sync them and it says it was succesful, but still they do not show up in my Strava profile.
During the run I noticed I did get 1 km updates of the stats but the pace was only right the first km, the other updates showed rubbish numbers for pace (slower and slower while I was actually accelerating)
So currently I am disappointed, dumping the app and reverting to Samsung Health.