Cup Queries

I currently use a Meluna in the Large size with the stem and with the classic firmness. In the last few months I've had issues with leakage even though the cup is not entirely filled. To be fair the cup is full up to about a centimeter or two below the holes so I'm assuming my cervix is dipping into the cup and I should change it more than every 12 hours, so that's mostly my bad. I've also had issues with some minor slippage, so that the longer I have the cup in it seems to move lower and lower. It doesn't get so low that the stem is uncomfortable, but it is low enough to stick out of the vaginal opening a few centimeters, and I can definitely feel it when I'm walking or sitting. I have also had problems getting the cup to open up once inserted in recent months. I switched from the origami to the punch down fold and that has helped a little bit, but I still end up having to move the cup around and stick a finger along the outside of it to assure that I've achieved a decent seal. Also I got this cup in December, just an FYI. So I'm not sure if I should just get a Meluna Classic XL or a Meluna Sport L or a Meluna XL sport or maybe even a Meluna Sport M. Any suggestions would be greatly appreciated!