I have a 5cd set of something, and when imported, it only includes two of the discs and the other 3 are nowhere to be seen. Its not that they have been imported with wrong or severed metadata. They just don’t exist.
So we can better assist you, please provide a brief description of your current setup using this link as a guide.
Make sure to describe your network configuration/topology, including any networking hardware currently in use, so we can have a clear understanding of how your devices are communicating.
What are the file formats of the disks that are not importing, are they FLAC?