I also experience a visual glitch with the regal miniskirt after the 7.3.1 update. During cinematics, it pulls weirdly in one direction and does not move with the character. I've tried swapping the outfit, unequipping the miniskirt and reapplying but it does not fix the problem. It happens with both the legging version and the no legging version.
Attached is a screenshot.
https://imgur.com/lvZvlTB