How to stop weird noises in top fin pf20 silent stream filter? Need advice asap!

I've got a 0.5 inch sponge media and a carbon cartridge in it, and I have it on minimum flow since I have a betta.

I just got it today and its been making weird noises for like the last 3 hours or 4 hours since I've gotten it. Multiple users have said its air bubbles that are left in the intake? I've tried everything to make it stop but nothing has worked.

I have 2 pre-filters attached to the intake since nobody sold the right size. I tired taking those to see if it woukd stop the noise but it didn't.

Advice asap would be nice since I need to fix this as soon as possible.