Ammo shop quick buy option always says $300 even after ammo is full and it will let you pay $300 for nothing.
I’ve seen this happen if you have a class mod which increases your Grenade capacity. Not new to the hotfix.
Confirmed on the fact that anything that boosts your grenade count will cause this bug, and that it’s been around for a while.
Yup, I’ve had that bug as well. It only took me $3000 to figure it out.