Cup issues and postpartum- help!

I’m 6 months postpartum and just got my period back.

Pre baby I had used the Saalt soft brand and I got the bigger size to begin with as I had a heavy flow.

Well yesterday I put it in and I kept feeling like it was about to fall out. Middle of the night I couldn’t pee with it in it hurt way too much so I popped it out peed, cleaned it and popped it back in.

However today, one of the times it felt like it was about to fall out as soon as I sat on the toilet. And then later on in the day I was getting ready to go on a walk with my dog and daughter and it felt like it was falling out so I popped it back in… and then once we left (like 10 mins later) I hadn’t even made it out of our condo complex and it felt like it was half hanging out. I ended up getting the mail and turning around and when I got home it was half out so I just took it off and put a pad on.

Is this normal post birth? Should I try a different cup brand? It honestly felt like my pelvic floor was just constantly pushing it out.

Help!