The signature weapon ammo drop rates have been rather low since the invasion update, and I think I remember hearing that it had been fixed a bit.
And yes, I did start seeing the ammo drop on rare occasions but I still feel the drop rate is too low.
It's not zero low, but it's so low that I hesitate to use my signature weapon because I have no idea when I'll see the next ammo drop.
Yesterday, I played for around 4 hours and saw 3 signature weapon ammo drop.
Today, I played for around the same time (maybe a little longer) and found zero.
(I use Survivalist so I've been burning my enemies to the ground as much as possible too)
I understand that you don't want the players shooting the signature weapons right and left but right now the sig ammo feels so rare that I might as not use it since I can usually go about without it. I do enjoy using it though...
If you are going to make the ammo this rare, wouldn't it be better if the signature weapon was buffed, so it was extremely powerful?
(Not that I mean it should be "one shot will disintegrate every enemy" kind of powerful)
Or slightly nerf the sig weapons and make the sig ammo drop rates a lot higher so we can actually casually use it when we want to.
At the moment, the signature weapons feel unbalanced.