Shall I change cups?

I've been using a larger sized uk Mooncup (well several) for over 8 years. I've recently converted a few friends to cups and have realised my experience of monthly leaks isn't typical. I have some small leakage most days in the first half of the period dealt with by panty liner and on heavier nights have to wear a full sized pad too/instead. Generally on heavy days (1-3) I have to empty it every 2 hrs. By day 5+ I can last 8+ hrs.

I've done some reading on here and had a check and am pretty sure I have a low cervix. Its easily reachable and I can squeeze the end of the cup and feel my cervix sat inside it. (I have no stem whatsoever on it as it rubbed). I can leak with a sharp cough or as I sit sometimes yet when I empty the cup its only full a third of the way up. Also sometimes it feels like the cup is falling out and I can feel it just by parting the labia - usually a couple of days into my period. I have no trouble inserting/removing it and am ok about firmess etc.

Ideas please what I should look for in another cup - shorter than the 50mm? wider than the 46mm? bigger capacity? all 3?