I used this for months and had no issues with leaking unless it was attached to the bottle incorrectly or the pieces weren’t put together properly. It only works when baby is sucking on it so it won’t show milk coming out otherwise.
Do you take the yellow bit off the bottom and screw the 4 yellow (clip looking bits) to the bottle? I think I've MAYBE figured it out. It's the only teat I've got that fits the bottles that comes with the pump
We have this, it is supposed to replicate breast supply, with drips and letdown. I think it's really annoying and leaks all over the place. If its not letting milk through when you suck, i imagine you have it wrongly set up (it's a bit complicated). The teat especially is odd - it just sits on top of the inner yellow insert (ie not in contact with the part screwed onto the bottle). Suck to see - it should let milk out quite easily if working