Gunbreaker running animation causing body armor to stretch oddly

When walking or sprinting with weapon drawn (or any movement with weapon sheathed) the "skirt" of the body armor (anything below the waist) moves and stretches normally. But when the Gunbreaker runs with their weapon out the front of the skirt flares up and out at an odd angle and stretches much farther than normal. The back of the skirt flares up too but not as much.

Character: Baraitar Nazzlohsyn
Server: Cactuar
Data Center: Aether
Race: Sea Wolf Roegadyn
Armor: Ravel Keeper's Vest of Fending

This bug affects body armor other than the Ravel Keeper's Vest of Fending, but I found it most notable on that gear specifically. Armor with shorter "skirts" (like the Holy Rainbow Shirt of Fending) will flare upwards when the Gunbreaker runs but not stretch as much.

https://i.imgur.com/aQOQMOy.png
https://i.imgur.com/Mly7F6U.png
https://i.imgur.com/EVCvjaQ.png
https://i.imgur.com/C5rXjh2.png
https://i.imgur.com/UbzoXrB.png
https://i.imgur.com/iDJPSeQ.png

Maybe sprinting awakens your 'other gun'?

Seriously, though, oof. I hadn't seen this on my catboy GNB, but I tend to avoid chestpieces with attached kilt portions, so I'm not sure if it's somehow the race, only a few particular items, or that kind of chestpiece in general.