When I look inside OneNote, to say add a new notebook, it will show me the names of the available OneNote notebook. So, I looked at the root level of my OneDrive for all files ending in. According to this web page all OneNote files end with a file extension that looks like this Oh yeah, well then where in heck is it? I looked in my OneDrive for it (I have a Microsoft 365 Family Edition license). Only OneNote than complained to me, saying that a OneNote notebook by that name, already existed. There was none, so I proceeded to create it.
I searched to see if I had a different OneNote notebook for the new that I wanted to create.
I realized that I was putting all these notes into the wrong OneNote notebook.