Hi @jerry_tung ---- Thank you for the report and sharing your feedback with us, sorry to hear of the troubles.
Moving forward, to help aide in our understanding in this behavior you are reporting with the N2520, may I very kindly ask you to please provide the following:
A brief but accurate description of your current setup using this link as a guide.
Please provide a screenshot displaying how you are trying to mount the NAS in Roon / error being received.
Please confirm that you have followed all the steps in our knowledge base article on how to configure NAS storage in Roon.