Hey GLITCH_COMMANDER,
This is a common problem when Fortnite Projects folder is being backed up by OneDrive or another cloud service. Because they aren’t communicating the changes with UEFN, they think the file deleted needs to be restored.
Don’t forget to Check-in Changes often, especially after you finish something you wouldn’t like to have to do again, this is Unreals Revision Control backup and creates snapshots you can revert to. If you created a snapshot when you published, you can revert the map changes back to how it was at that time using the Revision Control>Snapshot History.