Physics chain keeps jittering - need help

I seem to keep going in circles so any help appreciated:)

Hey,

I just made a physics asset and for some reason I followed every step of this tutorial

Halfway through the video he tests it and it goes haywire, and I followed the steps after to fix it but no luck. Is the video outdated? Can someone show me the steps to create a working chain from a skeletal in unreal?

Any luck?