My platform is PS4, currently Level 22 with GZ Up to current date. Its not a big issue but I encounter it a lot, if I engage a tank (Military or FNIX) and pop shots at it with the 50.cal rifle, over time it will begin firing its machine gun continuously in a random direction while still lobbing missiles at me. Ive encountered it about three times now, I have also noticed this mainly from any form of Runner but after a prolonged Fire Fight while out of enemy sight such as inside a bunker they still shoot. Like I said not a game breaking bug but it does grow tiring hearing Runner fire while looting a large bunker.
Same thing with hunters and tanks. They will fire a continuous stream of Mgun fire, or very occasionally, missile fire.