Annoying bug that seems to occur almost every time i spawn in as demolition class. i think what triggers it is when i cycle through my gear when i run out of spawn. The launcher still works but you cant really use the crosshair and there is no animation for reload so it is really hard to know when you have reloaded.
I've even spawned in once with two separate underbarrel grenade launchers! There would be two underbarrel options on the right side were your weapons are, the first would be bugged just like that, but the second would fire just fine lol. At least I had twice the ammo!