Is the software on your phone up to date? Go to Apps > Settings > Software update > Download and install. Also, let's try a Soft Reset on the phone. This will end all processes and give the phone a fresh start. To do this, press and hold the 'Power' and 'Volume Down' buttons until the phone restarts.
Let us know how you get on!
Hi I am facing the same issue with my galaxy watch and I have the note 9 phone. I am on the latest software update for both phone and watch. I have tried to do a soft reset but that hasn't worked. Does anyone have any other suggestions? It was working fine before the time change.
Same issue! A few weeks ago it wasn't showing any accurate sleep data, just the general length. Did a reset on my phone (Galaxy S20+) and cleared the cache on the app, also restarted the watch (active 2) and that seemed to fix it. Then this morning I check and the times of my sleep and workouts were off by an hour, ahead of current time even. Another cache clear and restart on both devices seems to have brought it back to normal and accurate time. Just did so, hopefully it stays fixed and I don't have to do that every day!