Pipette Gun Bubbles?

Hi all,

I've noticed recently that when I try to dispense the liquid from a 5mL serological pipette drop-wise, there seems to be some that gets stuck in the bottom of the pipette. In order for me to get this out I have to push harder on the dispense button and it creates a bubble in the media or whatever I'm currently working with.

I have put my pipette gun on both slow and fast and have the same result.