SFAR-M GL: Grenade launcher mod getting stuck bug

This is getting annoying, it happen many times when switching between normal mod and under barrel mod, my gun start firing normal bullet as projectiles 😠.

it happen when you switch quickly to normal mod after firing a shell, I think you need to have 0 shells left, I can get around it by using the plus system but I would be long ago dead :/

I have not tried this with the other guns.

is this bug known ??