>>398924930
Because I haven't made a tutorial on how to do it properly yet. This is a fix that I figured out on my own with some help from a friend
This is actually a bug in Unity's new "Animator Tree" system that VRChat uses for Avatars 3.0. The old AV2.0 didn't have this issue so it's hardly mentioned, and there are some very specific and weird things on your avatar that trigger bugs like these. Another big one is having empty states on your controllers with no animations in them, this should be avoided. Use a 1-second long dummy animation clip instead.

You can avoid all of these issues in AV3.0 by never using Write Defaults, and then using a reset layer above your facial expressions layer to reset your facial expressions instead. For object toggles, have a separate "on" state and a separate "off" state that each explicitly turn the object on or off.