Been having this same issue - and I also have the mod installed. I don't think the mod has anything to do with it since the ship is like stuck down when this happens. Once the vengeance goes down either by being defeated or by the test menu, it comes back up very slowly and I cant move it by hand - like every time a bumper bumps the ball, the Vengeance moves back into proper upright position by a little bit. After a while its all back to normal.
Going to check for this metal tab.