My WNSS are still leaking?

Hi there everyone - I'd always used microfiber boosters in my pockets until recently and was none too impressed by the amount of damp vests we were getting - but I found some small prefolds which I wrap around a small little lamb bamboo booster and the difference is amazing haven't had a damp vest for weeks well only if I've forgotten to change it and it's sodden - Bad bad mummy