MAM bottles bubbles

Hi everyone, my little girl is 2 weeks old, we’ve recently switched from TT anti colic to MAM bottles as the tommee tippee teats were collapsing very easily and stressing her out, plus taking a long time to feed. I was squeezing the vents before use and not over tightening the lid, no luck!

So the switch to Mam bottles and we’re having pretty much the same problem, I can’t hear the vent working and my little one has to release the pressure in her mouth to allow more milk which then bubbles flow up the teat into the milk? Still taking a long time to feed and we’re very messy with feeding times as she’s falling asleep during a feed and then waking 1 hour later for a top up!

I’m sterilising the bottles all components separately in an electric steamer, do all parts need to be completely dry before assembling?

I’m trying lots of different variations on the bottles such as tightening all parts, loosening the teat lid or bottom vent but we don’t seem to be figuring it out. Plus loosening some parts is having milk leaking everywhere! 🤣

Does she need a faster flowing teat? The next size up are recommended for two month olds! I’ve googled the question and emailed mam but had no reply from them yet!

Thank you for any help or ideas!! 😊