iPhone “Notes” app. Limits?

Is there an upper limit to the number of notes you can have on your phone? Is there an upper limit to the number of characters you can have in a single note?

I ask because I’m transcribing a document written by my grandmother 50 years ago by dictating it into the notes app on my phone and then sending every three pages or so to Apple “Pages” on my computer. Once I have dictated about 3 to 4 full pages, the notes app starts getting wonky. Sometimes displaying only a blank page, even though I know something is there. In one instance not allowing to send the note via airdrop, though I checked and other smaller notes were able to be sent.

I have plenty of room on my phone, about half of 256 gigs.