Roon always lost NAS connection

I encounter another very annoying problem. When Roon is playing music, there is a running circle on the top right hand side of Roon. Roon seems always scanning NAS but I don’t have any new music added into NAS. Roon sometimes suddenly stop play music because it said the track is unavailable. After a short while, Roon can play music again cause Roon can read music in NAS again.
Could you tell me how to fix this problem? I am using AudioLinux with latest Roon version.