I found that if you attempt to place any decoration like the Luftfaust-B or RPG-2 on the Turan II upper rear armor just behind the radiator the item will place but after closing the menu, and switching to another tank the decoration will vanish entirely. placing decals in a similar area does not trigger this cosmetic glitch. all other locations on this tank accept decoration items as usual.
I attached a screen capture of the decoration placed w/ a decal in a similar location - the moment you switch vehicles however only the decoration placed on the rear armor vanishes.