Here are some issues I encountered when trying to scan to a Samba file server that is connected to a Samba AD DC.
1. Setting up the "Scan-to-FTP/Netzwerk-Profil" works. But scanning to that folder fails.
Symptoms: The configuration test will come back with being successful. Also selecting the profile from the scanner menu works. After scanning the document, an error message is displayed on the screen.
Solution: In the destination folder config, replace the "/" with "\". Root cause is unknown. Maybe the file server does not replace the "/" automatically. Note that this is not reproduceable on all file servers. The "/" does work on other tested devices.