You might need to replace the parts, you should be replacing the duck valve every few months. When the parts get older the milk output decreases
I don’t know if it’s called the duck valve or if I’ve made that up by the way, I think that’s what it’s called? 😂 the triangular part where the milk spills out into the pump 😂
Have u replaced parts yet? I had to replace a couple of the silicone parts and it started working like new again