Good example, thanks for sharing. That also demonstrates my issue except, apply that issue to jiggle physics (Physics Asset with 2 joints with constraints per breast) and its the same thing on my end. Im guessing thats done with a chain of joints inside a Physics Asset with constraints?
My characters hair uses nCloth, but I havent gotten around to updating my hair nCloth settings since 4.16, so Im not sure if its affecting cloth physics, but I wouldnt be surprised considering I had to enable substepping to fix jitter with cloth physics in 4.15.