The suction sound and a different feel this time

Just how important is this suction sound when putting the cup in? I am trying to practice insertion with my small Lunette because AF will be here in a day or two and when I did my dry runs it seemed to pop right open and I heard a suction sound, probably not every time I inserted it, and it seemed to fit OK and be comfortable. Only when it was low could I feel the stem, but it didn't bother me.
I started spotting very lightly today, so I boiled the cup and cooled it under cold water and then put it in with a "C" fold (I did make sure there was a hole where the fold was, but I don't remember if I inserted it with the fold pointed sideways or not). This time there wasn't a suction noise and I can move the cup up easily. I can also pull it back down easily up until the pelvic bone then it seems to stop moving and I'll pinch the bottom cm of the cup (about where those grip lines are on the bottom) and it will collapse completely which it took a little more work then that before during the dry run. Right now as it sits only the stem only sticks out to the first grip line and I can't feel the stem at all, so I'm sure it's a little too high. I tried to pull it lower, but it seems to want to be higher right now.
I also ran a finger around the outside of the cup and it seems to be open all the way, but it spins pretty easily and kind of feels like it's too small. Which that would be weird because it seemed OK when I did the dry run.
So I'm also wondering if vaginal walls relax a little right before AF making the cup have a looser fit? Or is it just too high? Will I experience leaks if I don't hear that suction sound even though it seems to be open?

Oh for sure the muscles relax more during AF. Not sure why, but they do.

I think rather than a lot of suction-- its more about making sure the cup pops open all the way, and making the fold crease face the side, or even backwards seems to really help.

I actually let it pop open about halfway in, then coax it up. Its because I have a low cervix, and that helps to ensure that my cervix won't get caught peeking out from the side of the rim or anything. It also helps it pop open more easily.