When you hit play to test an animation in the editor none of the parts will move, but visibility will still toggle properly. This doesn't affect the ingame animations which play properly and have had the bug with visibility toggling fixed.

In my case, the default animations and positions partly overwrited my custom animations in the editor even though they test fine in-game, which makes any further editing to my custom animations super tedious, as now I have to compensate using my mind's eye instead of using the model as a visual reference for positioning and rotating.