EDIT: I am aware that the incorrect force (The part dancing around when you spin) may be a result of not using rigidity. There’s another part to this bug. Here’s a gif to show you. The part is getting stuck entirely, yet is suspended in the air and has no objects touching it
Thanks for letting us know about this bug. We are aware that there are issues with constraints + humanoids. The main problem is that there are times that the humanoid is not physically simulated, making the constraint misbehave. We have plans to fix this.