In my case, it was always due to a lack of vacuum. I would recommend checking that everything is tightly sealed and that, apart from the opening at the top, no more air can get through anywhere. Maybe that will help :)

Hi Nadja, I had the same problem! I realised that when you put the large parts together, you really have to press them very hard to make sure they are properly inserted. I often place it on the kitchen counter and push down with my hands. If it isn’t inserted fully, then the vacuum can’t happen as there is air entering. Also check the size of the Falange/nipple insert and make sure it’s the right one for you.

Would like to know the answer too, I have the same issue. Considering sending it back

I have the same problem, got it to work a few times, but today I didn’t manage to get any vaccum. I’m using the 15mm in the 24cm breast shield since it fits, but can that be the problem? What are you using?