Sounds like there could be a couple of issues as the others have said. Microfibre can squoosh (that is a technical word
) wee out when it has pressure put on it so that may be contributing. As already mentioned the vests could be causing issues too. You can buy vest extenders that give you an extra few inches of rise. To be honest I gave up with buttoned vests quite quicly (maybe 6 months). How old is your lo? You're not washing with fabric softener are you? This can reduce absorption. How quickly are the leaks happening?
Do keep at it - once you find your perfect combo you'll be away
I have one, maybe a bit stupid, question. How did you keep your LOs back covered. I hate poppered vests, but its the only way I can keep her back covered. The only time I put her in some leggins and a top, she was barebacked in no time. I usually put her in a poppered vest, then thights and if its really cold, warm pants and a top over it. I was considering leggins and a tunic, but vests are still more snug to the body and thus warmer.
How do you clothe your kids, if you dont use poppered vests? Thanx!