I noticed an item despawn right before the next wave, I don't think it's that, but it's a possibility.
sorry for making it such an eyesore, it was a 3 minute google slide collage. This was my build. Forgot to show that my turret was using the snow slow. Another bug I found was that when you have triple blasters and use an item that only has 2 ammo left, It briefly goes to -1 then to zero, then reloads. The problem is that it still fires three bullets.