Unable to connect HQPlayer after transfer core from original computer to another

Core: Win 10, build 756 stable
Remote: Win 10, build 756 stable
HQP: 4.5.1, output through rpi3 NAA

After transfer core from my original computer (now served as remote) to a new one, I cannot connect to HQPlayer anymore both two computer. I have changed the HQPlayer IP to the computer which operate it. Using HQPlayer as player is normally functioned. And I have checked the “allow control from network” button is on. Besides, I can play from the remote computer with enabling direct audio output.

When I played any music, it loaded for about 15 sec to show the connection problem, and the reaction time was not similar to the problem caused by HQPlayer not operating or its IP error which react immediately. So I guess my HQPlayer can be detected by my core but cannot transport music into it.

What the connection problems might be?

Thanks!

Firewall possibly blocking connections either way? Same HQPlayer settings as before?

Roon needs to be able to connect to HQPlayer and HQPlayer back to Roon.

Enable HQPlayer log file, restart HQPlayer and reproduce the problem. This way you have a record of the problem. Also keep eye on HQPlayer status bar when attempting to start playback for any possible error messages.