Harald wroteCould you perhaps send us a minimal version of your Unity project that still shows the issue? You can send it as a zip package to contact@esotericsoftware.com (and in the email shortly mentioning the url of this forum thread so that we immediately know the context), then we can have a look at what's going wrong.
I think I found the issue trying to reproduce the problem in an empty project.
We have the Update When Visible set to Only Event Timelines on a few SkeletonGraphics. The thing is, with that setting the assets work perfectly fine until the update 3.8-2021-06-01 where the assets won't update at all.
If I set this to Full Update with the last update, the animation states do change, but the animation is still not played correctly.
Maybe you have some thoughts or some tests I can do to really know what's going on?
EDIT: the animations apparently do work with Full Update, my bad.
So, I reckon there are some changes from the previous version to the last version affecting the Update When Visible parameter? It's weird because the SkeletonGraphics I am using are on the HUD and they are always visible.