Why are there so many Rem in my left sidebar?

I took some notes in my French class, usually one document-Rem with about 100 sub-Rems. Some of these Rem are in the sidebar. I don’t have them tagged as Document themselves. Why are they there? They are clogging up my sidebar. Things like a single Rem: “Non…sans–Not without (page 177)” are in the sidebar.

Here’s a screencapture of the breadcrumb trail, so you can see how random it is. I wouldn’t have hoised this empty rem titled “spoke French…” to my sidebar.

Here’s how my sidebar looks with some of these random Rem as documents:

And here’s a section called “Oligations”. The “falloir” Rem shows up in the left sidebar, like it’s a document. The other rem don’t.

Moving them all is so tedious. And I don’t know why some are there and some aren’t so I don’t know how to prevent this in future. Could it be some remnant of restoring a KB to my local machine?

Also, I notice the same issue with PDF highlighted notes. Some random notes appear as Top-Level Rem in the sidebar. Other notes from the same PDF don’t. It seems totally random.