Strange grenade launcher behavior

I found myself a Humvee with a 40 mm grenade launcher - yay! But when I fire the launcher the grenade explodes right on the Humvee. So I take it off and use it by hand - and the grenade explodes on me, as though I had targeted myself. This happens completely consistently. I am properly selecting targets far away. Distance of the target doesn’t seem to matter. Is there some extra step I need to do to use a grenade launcher? I am using generic guns, if that would somehow affect things (all other guns I’ve found work fine).

Sounds like a new bug, I’ve been using a grenade launcher since forever ago and never had that happen.

Probably there’s no roof on the humvee…

Probably there’s no roof on the humvee…

Why would the roof matter?

Have you tried repair the grenade launcher first? mabye because the launcher are damaged, so it may be the reason that it can’t shoot well, try again once you repair it?

Have you tried repair the grenade launcher first? mabye because the launcher are damaged, so it may be the reason that it can’t shoot well, try again once you repair it?

Just tried it. Fully repaired but still explodes on me.