Notes in Nextcloud not deleted when they are in Joplin

I have the opposite problem from the one in the FAQ. Preliminary to moving the sync location for Joplin on NC I moved all Joplin notes to the new location, then deleted them in the client and synced. Then pointed the client to the new location and synced. Fine.
But the problem is, when I open the old location on NC, I see all the notes there, even though they have been physically moved to the new location. How can I get rid of the listing in the old directory, which I now use for a different purpose?

This has been solved, by rescanning all files in Nextcloud. Problem solved.