So, I was kinda bored and tried Battle. Killed a monster and it was already time for a rest. 5 hours or so remaining. Next day I checked it again: still the same amount of time remained. Cleared cache - for no effect. However when I refresh I see that the timer works. Until it reaches zero. Then the next refresh shows a negative amount of time, and another refresh puts back the timer to the start. Very annoying.
Any ideas to fix the problem?