cup keeps leaking?

i’ve used my saalt cup for my last two cycles and it’s been amazing-no leaks and i forgot i even had my period. this is my third cycle using it and each day it has leaked and i don’t know why. i’m putting it in the same way but i can still feel the blood coming out (TMI sorry) and it’s obviously leaking onto my liners, but there’s still lots of blood in the cup when i empty it. it’s not just overflowing either, it happens when i first put it in. any suggestions?