Notes deleted after account made

I sent feedback through the app and tried to post something here a couple days ago, but I still haven’t recieved a reply so I decided to try again.

I’ve used the Notebook app for a year or so on my iPhone and have loved it, but two days ago when I finally made an account (a little late, I’ll admit), most of my notes were deleted; out of maybe thirty or so, only nine survived. They aren’t in the trash or anything either.

As I said, I sent feedback with my user log two days ago when it happened, but I’m still awaiting a reply.

I was wondering if anyone here had any insight. Was it some sort of glitch? Is there any possibility I can get them back?

Thank you.