Ugh how frustrating for you
Any kind of pocket, all in one or the like would've leaked for us too at that age and thats with hemp and bamboo inserts. They just weren't suited to my kids
. I did use them when they were older and more mobile, mainly for nursery but they would never last long and then at around 2 would flood when they held onto the wee for longer and let it all out in one go.
It sounds like a two part system does and would work better?
Prefolds were always our most reliable system as I couldn't afford many pretty fitteds. The wrap does get wet/ dirty so you do need more of those but at least I wasn't having to change and wash clothes. I found them less bulky than terries as its just bulk between the legs rather than all round.
If you put a request out there could be people local to you that would give you some for free, they hold very little resale value.