Hi @jin_cheng,
Thanks for following up!
Do you have any active firewalls tied to the Mac running Roon Server? If possible, can you temporarily test out disabling your Mac firewall and see if your issue persists?
Any VPNs you may be running will need to be disabled as well, as these fall outside the scope of our support, unfortunately.
With that, if there are any larger firewalls at play, Roon isn’t equipped to guide how to bypass state firewall restrictions, but users have gathered useful anecdotes in threads like this: Is Roon banned in China?