OK nevermind, to anyone who sees this post, I just found out the problem. The author used the VRC proxy_hands_idle motion on the Idle State of the Left and Right Hands Expressions in the FX Layer. If you have a similar issue happens to your avatar, the solution might be delete the IDLE STATE MOTION of Left and Right hands EXPRESSIONS in the FX Layer if the author used VRC’s default proxy animations. I guess the problem is the conflict between the proxy_hands_idle and other customized hand gestures. When the proxy_hands_idle in the Gesture Layer transits to other gestures, it conficts with the transition from the proxy_hands_idle in the FX Layer since this proxy animtaion contains a hand gesture.