Custom Animation Overwrites Arm Rotation

I have made a script where the player’s arms would rotate depending on where the camera looks using Motor6D.C0.CFrame and am currently trying to make it work for both R6 and R15.

The problem is that if I play a custom R15 animation that involves any joint in the arm, the rotation will barely take effect / rotate incorrectly. However, the default R15 animations don’t have this problem. R6 does not have any problems with this.

Even if the shoulders do not have a track in the animation, any animated part of the arm causes this issue. Setting the position of C0 has no problems, only orientation. The CFrame is set every RenderStepped.

This is a follow-up post to a previous post I made.