None of my remotes (even the pc server is on) can connect to the roon server. I have restarted the pc. Reinstalled the app. Even had geek squad look at it.
If you’re not able to connect to Roon even on the server machine itself, then the most likely culprit is the Windows Defender firewall.
I’d check in your Windows Settings whether the Defender firewall has RoonAppliance, RoonServer, and RAATServer added as exceptions (safelist). Sometimes Windows updates will reset the firewall.