CloudLink - Cannot log into CloudLink WebUI if I specify anything other than port "9000"

If I specify anything other than port "9000" in the Mx.CloudLink.exe.config file, I can browse to the UI landing page but I get a "Network Error" if I try and log in.

Example:

• Update ApiBaseAddress, set the port to anything other than 9000
  • <add key="ApiBaseAddress" value="http://localhost:9500/" />

Browse to http://localhost:9500 and try and log in:

There must be some kind of routing issue