Thanks for opening this question.
Tool bar just below timeline has a percentage indicator (just left of "normal mode" tool icon) that shows up when kden slows down or locks up. Is there a way to reset other than closing down kden?
Might not have any similarity, but I wondered if there was a "flush cache" like in Adobe After Effects. Occasionally something challenges Keden and system locks. Most often the percent indicator displays when I have issues with audio sync.