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.
Just to verify here, there are certain folders in your library where the content is not showing in Roon at all?
First, I’d like to point out some documentation we have that may be helpful here. In our KB we have an article about Skipped Files and an article about why some files might be missing from Roon .
If you go to Settings > Library > Skipped Files do you see any of your missing files there?