If the Panther's #5 spot "AA Mount" is used and turned to any direction then the player switched to position #1 or #4 (possibly #2 as well) and then switches to position #3 the Gun's Mount is in the default position and the gun floats. If going from position #5 to #3 it works like normal.
Pictures:
View is moved to show it, gun that high isn't part of the bug
