My notes font is set to default, and I never touched the settings, yet one note turned up in Helvetica Neue, while everything else is in Athelas Logos:

Also, it keeps pasting something older than what I last copied. The reason the first note says 'Gen' and not 'Genesis' is because I had to write it in manually. When I tried to paste the Bible reference, it pasted one of my forum posts instead! The first time, I, naturally, thought I hadn't pressed the keys down properly, but after that I kept my eyes open and made sure the Edit menu flashed. It still pasted the same forum post two or three times in the note, and twice in the hyperlink box, before I finally managed to make the copying 'stick' and paste.
But then look at the next two. Again it's pasted the same thing in note 3 as in note 2, in spite of the fact that I made a new cmd-c in between.
Problem one has occurred several times before; problem two is new.
(BTW, the fact that note 1 is entered manually is not the sole reason for the different font. After the screenshot I made more notes and typed text into them. They used Athelas.