You are clicking the (possibly faint) second down arrow at the far right (adjecant to the area that shows the suggested folder) that opens the full bookmarks tree and not the arrow in the field with the folder name that shows some favorite locations?

he Folder line in "Edit This Bookmark" that opens if you click the highlighted star in the location bar has two drop-down arrows. The first arrow is in the field that shows the name of the folder opens a drop-down list that shows the main bookmarks folders and some folders you have used recently. The second arrow, that might be harder to notice, is to the right of the folder name field. That second arrow shows a tree list of all bookmarks folders with the folder where this bookmark is saved selected and where you can select another folder to move the bookmark to this folder.

See "How do I change the name or location of a bookmark?"

• https://support.mozilla.org/en-US/kb/bookmarks-firefox

Thanks for your prompt reply. That did help clarify the issue. Mostly, it seems to work, but sometimes gets out of wack and scrolling stops works. I'm not sure what makes that happen. However, closing the browser or restarting my laptop seems to fix it. I can deal with this - thanks again.