I have an Asian 21J Omega Seamaster GMT with a very strange behaviour.
On the wrist the watch keeps perfect time and seams to wind just fine.
When I take it of at night and leave it on my desk the hour, minute and GMT hands stops after a couple of hours BUT the second hand keeps running.
I have watched the second hand for a couple of revolutions and it works just fine but the minute hand is completely still.
When I set the time it sometimes feels a little bit rough.
When the time is set the watch runs perfect again.