Hi @Hoa_Pham,
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.
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?
I’d like to recommend looking at a couple of specific examples of tracks that did not get imported into Roon. Are they supported files? Are they showing up in Skipped Files? If it looks like they should be importing, let me know! Screenshots of these files in their storage location would be helpful for discovering what may be happening.