Animations are not looping

I just discovered this the other day-- animations that I had on loop, such as those from marketplace purchase tokens, or gifs used as token images-- now appear to only be running through one cycle and then stopping. I can r-click the token and hit "Play", and it will play through again, but only once and then stop again. I was NOT hitting "Stop Looping" so there is no good reason the animations should stop. Is this a new known bug?

Yes, others have mentioned encountering this bug.  See Animations Won't Loop . I haven't tried the fix myself, but a work-around mentioned in that thread is that while some existing animations and new  animations dragged from the art library won't loop, you can copy an existing or new animation, then paste it, and the pasted copy will loop normally.