Leaky cup

I’m using meluna sport cup for almost year and a half and it never leaked. But last two cycles it leaks on the first day. I never been pregnant, my weight is the same and I didn’t have p in v sex for years, so I’m pretty sure that the size of my lady parts didn’t change. Cup also looks the same. Every time I put it I have a seal, and it’s not full to leak when I get it out, so I don’t have an idea what’s going on. What it can be? It’s really annoying cause my lady parts are sensitive and using a pantyliner irritates me.