Hi, I am getting this problem now since the most recent update, 5.1.1.
I have a Gear S2 and using face TACTICAL DTG THEMEABLE V5.
I have tried clearing cache, uninstalling/reinstalling with no luck. Once you apply the face it works fine but once the watch has been asleep for several minutes it doesn't wake up and just shows an image of the time it went off.
I have tried setting AOD and this doesn't help, it seems to be ok for a few minutes and then freezes up again and stops displaying completely, leaving a black screen for AOD.
Everything has been working fine with the app and this face up until the update in December.