Can only insert when lying on my back?

I'm on my second cycle with my Meluna classic medium and after the first cycle I have sort of figured it out and all is going well. The only problem I'm having is that I can only get the cup to pop open when I insert it lying on my back. This is a bit of a problem as it means I'm having to go back and forth to my (shared) bathroom.

Does anyone have any tips as to how I can get it to pop open when I insert it in a sitting/squatting position? I've been using the 7 fold but it still takes some poking to pop it open even when I'm lying on my back.