Maybe some efforts at fixes or bugs are cheats???
My wife's had this happen several times, son a few times and twice for me with our AW2s. Your workouts don't register for your overall day.
A few days ago I had a 2 hour hike that covered miles done as outdoor walk open goal and a 1.4 mi walk with the dog. The green ring showed 23 minutes of activity. Various efforts to fix it didn't do anything including restarts. Late in the day I did 7 min of stretching and calisthenics and when that third mini workout was done both the watch and phone registered the 2+ hours. I'd call that a cheat because it was not particularly strenuous and mostly done to see if I could fix or change that not moving the rings problem.
Beyond that I don't know what cheating would be. It seems like since having the watch stuff my phone used to record needs my arm swinging so I'll think of keeping the watch hand free if I carry something across a building etc... That's really rooted more in wanting to know how many steps or miles I move.
I never seem to take the watch off during the day so is washing dishes, pots and pans cheating? Is putting the watch in swim mode when it might get wet cheating? I haven't looked in detail but if that makes it think you're swimming a few showers might have been cheating.
