Sounds like the WSMAN Listener needs to be recreated as outlined in the following KB Article.
Simply delete the the listener on the server you are trying to monitor "winrm delete winrm/config/listener?Address=*+Transport=HTTPS" then re-click the Configure Server" button. If that doesn't resolve the issue it may be a permissions related problem. I would suggest looking through the following log file located on the server you're trying to monitor using AppInsight for IIS. Look for any errors or simply post the file contents here. Alternativly, you can also open a case with support.
- "C:\ProgramData\Solarwinds\Logs\APM\RunWinRMConfigurator.log"