Harmony 22 Play Button is glitchy

The play button is very broken. It often gets stuck on a frame and makes the animation go out of sync. When loop is turned on it will loop the first 6 frames instead of the entire animation. The only way to see the animation in real time is to render and play which can get annoying.

I only started encountering these problems once I updated to 22 (Harmony 21 was fine), it can’t be the file size because it does this even if theres only a few drawings in a NEW file. Is there a fix to this?

Yes it is bugged, report it to support. And here are posts on the topic.