Those aren’t that great, I believe they are microfibre. Miosolo aren’t very popular in the cloth world for a reason. I use Mama Koala w 6 layered bamboo inserts and they don’t leak on me. But also, if they’re new they’ll need a couple washes to get to max absorbency if they are brand new they’ll still have oils in them that needed to be washed out. Is that the only brand you have?
@Penny thanks I'll take a look!
@Kellie interesting! Majority Miosolo, some Revolutionary (which I find don't leak, likely due to the contoured fit), all been used a few times as well.
Have you tried hemp or bamboo boosters? If you are based in the UK, this Facebook group is great for advice. You can use the search function to see if you can get any tips or post in there too. I've found it very useful when I was having similar issues. https://www.facebook.com/groups/TNLParentGroup/?ref=share