When you move a bookmark, it should remain where you put it. New bookmarks should be placed at the bottom of the selected folder.

Note that sync or sorting the bookmarks can change those positions.

FredMcD said

When you move a bookmark, it should remain where you put it.

OK, I misspoke. Cut & Paste does work. The technique that did not work was to use the "Views" tab, selecting Sort by Name. I expected the resorted list to stay in place, but on restart, it reverts to pre sort order.

New bookmarks should be placed at the bottom of the selected folder. Yes, this is where new bookmarks go.

Note that sync or sorting the bookmarks can change those positions.

The Views menu in the Library is for viewing purposes only like its name would suggest and doesn't sort the bookmarks permanently. Like you noticed, you need to use "Sort By Name" in the right-click context menu of a folder to sort bookmarks permanently.

Thanks, cor-el. Right clicking on the folder in the left column fixed the problem.