Backup creating strange files on Synology NAS

David please check the folder names via the FileManager in Symbology’s DSM desktop. If my hunch is right you will find the folder names all in tact via FileManager. If my hunch is correct you’ll also find that the folder names have used a special character not permitted SMB. Here is a link to a thread that I worked out a similar issue.

Hopefully my hunch is right and this helps you.