I had a run and pause an activity for a few minutes, but after that press to any options(Resume, Resume Later, Save), Start(unpause) or Back button. just trigger the animation(unwind) but not any real actions, and animation unwind to the same "pause screen" - so basically press to any anything cause a recursion on the screen.
After the restart the watch it start to work again.
Software version: 6.17
When I mean "pause screen", I mean this: