I also have a Synology NAS where I wanted to put the archive. The SMB folder is mounted via the Apple automounter. When I specify this for the archive I get an error message. However, if I mount the folder using the normal mount behavior of macOS, archiving works, although both mounts address the same target. Then even when I reopen the Diskstation folder it mounts when it didn't.
My app uses a shell path to write the location of the database to prefs and uses the path to open the database. For the user the path is "/Volumes/Privat/MailArchiverX/MailArchiv.vdb".
Do you have any idea what might cause such a problem. User is using Catalina with Valentina 10.5.3. The database is a local and not a server one.
