Why am I seeing duplicate folders and items on the Destination after migrating from Dropbox?
This issue is a direct result of the Dropbox API, where sometimes a folder is presented as "Folder A", but the next time it's retrieved, it is instead presented as "folder a". This causes duplicate folders to be created at the Destination. This, in turn, results in duplicate items being created at the Destination, because the same items will then be migrated into the duplicate folders.
If this occurs, there are two possible options: