All movement scripts seem to make the character’s arm bend inwards and ruin the animations:
The fix for the animation blending by using the RbxLegacyAnimationBlending attribute doesn’t seem to work this. I believe I’ve found a solution by reading through this post: Animation arms bend inwards when modifying roots - Help and Feedback / Art Design Support - DevForum | Roblox, specifically the comment made by @tytyknight. By disabling Retargetting under Workspace, this seems to have the effect of fixing the animations, arm bending, and the movement scripts. This may not work for any other movement scripts but the ones I use, and I’m not a programmer, so this could come with unintended consequences.