Hi,
yesterday I had a workout and the timer was stuck. Even if I pushed lap, it was switching to the next interval but the timer was not running (at the top).
I guess it was due to auto pause and manual stop for a gas station stop for refilling. After that I started again and the problem was there. I noticed later that a short stop and forcing auto pause was fixing the problem.
Here is video of the problem (sorry for shaking):
