Created attachment 378679 [details]
Open the attached test case. It has two animated rectangles. The duration of both elements is 2s. The repeatDur of the first rectangle is 4s while it is 5s for the second rectangle.
Result: The first rectangles freezes at where the last frame is drawn. The second frame is moved back to its frame drawn at 3s.
Expected: Both rectangles freeze at their last drawn frame.
Related WPT tests:
It seems that I didn't done my due diligence properly - I am fixing it via bug 250977. Once other will get committed, we can mark this as duplicate of other bug. Just wanted to highlight.
*** This bug has been marked as a duplicate of bug 250977 ***