This affects all versions 1.9 and up. The right hand (left) looks like how it's always been, while the left hand, (right) looks like it's just flailing around, and no this isn't caused by the plugin I have. I've noticed this in every single world when I was just messing with skin settings.
MC-163406
Left hand movement is much more exaggerated than the right hand.
Resolved
Duplicate
2
Can confirm. I've attached a video to better showcase the bug. I don't think you can say it's exaggerated, but it's at least a bit different from the right hand animation.