There is a super-annoying bug while doing “find in note” in the iOS 17 version of Notes.
If it’s a longish note and there are multiple finds, when you clicked the > arrow it used to jump to the next found item. It stopped doing that, so you can’t find anything!
My temporary work-around is to open the note in Pages and search there.
I sent in Apple feedback about this. Their bug report version drop-down doesn’t let you select iOS 17 yet. Hah.