Since I can't reply to that post and it got moved, I have more info I'll post here.

This bug also affects Miqo'te tails and seems to be linked to a physics engine failure. When this bug happens, my legs stop clipping my robes as I run because the cloth physics have also stopped working properly.

As an aside, I'd like to suggest allowing us to manually toggle that off, as I prefer the bugged version. I dislike my long robes clipping my legs and they don't when the "tail bug" happens.

Just thought to give a heads up on connected issues to help track it down. I'm convinced it's the physics attached to loose things, cloth, tails, possibly hair(have not tested).