Have tried everything - still leaking

Hello! I was wondering if you guys could help me? I've started using menstrual cups about 5 months ago and I absolutely love them except for one thing — the leaking. I started off with the mooncup size b (smaller size?) and it worked on the first day.However, soon the leaking started (random times). I tried everything from always checking if it popped open, running a finger around the rim, wearing it high, low, inside out etc. Still leaking. So I bought the lunette (bigger size), which is made from a harder material (thought it could be because my muscles were bearing down, squeezing the cup and causing an overflow). It all became a bit better and has now settled down to this: I can wear the lunette on the first day, the third, fourth, fifth and 6th and 7th day (If I have a 6th and 7th day). On the second day the blood is bright red and very liquid, on the other days darker and with a higher viscosity. The bleeding is also very strong on the second day, with the first and the other days being very light. (When it leaks, the cup isn't full). However, the lunette should work no matter what. Again I tried all the 'basic' tipps I could find in the internet, so I would really appreciate it if one of you could help me! I have contacted lunette and mooncup but both just gave me the 'basic' tipps such as: make sure the cup is unfolded etc. Does anyone know why, or is experiencing the same? Thank you in advance!