Roon Server on Windows Server, Can't Connect

What do you mean by ‘opened inbound ports for RoonServer’?
You need to add exceptions to the firewall for Roon.exe and RAAT.exe.

Usually the best thing to do is to just turn off the firewall completely to see if everything is working. Then you can add in the exceptions, and turn on the firewall. If turning off the firewall doesn’t help. it could be multiple issues.
I’m moving your thread over to Support, where it belongs. If we can’t get this going for you quickly, then the Roon Support people can add more firepower. I’m just an experienced Roon User.