I was having the issue with my Gear Sport. It also measured 20k steps when I was just driving around one day. This was after I reset the device. I contacted Samsung support and they ended up fixing it under warranty. So far so good.
Im having the same issue too and this is on the new Galaxy Watch Active. I don't mind it as I can go into the app and delete the miscalculated sleep but it's a bit of a nuisance.
So i contacted samsung about the watch tracking sleep when im awake
I was advised to turn the heart rate tracking on permanently
I have done this and so far its been working as it should
And nonreal difference in the battery life
Ha thanks for the update
How long does your watch usually last for on screen on mode? also what type do you have?
I have the 46mm and it last about 2 days (dies at night of the second day) I'm worried turning the heartrate monitor on permanetly will decrease my time to one day only.
I have the same problem, tracks me as still sleeping 1 hour after I've gotten up, sleeping when watching TV, and says that I'm inactive while I'm out and about. I had a Samsung gear fit2 before and it didn't have any problems