Here are a few commands which can be run to troubleshoot Windows Remote (WinRM) connectivity (These commands may need to be run on an elevated CMD):
This shows you which port and IP addresses WinRM is listening to:
winrm e winrm/config/listener
This checks if WinRM has some problem:
This shows you the configuration:
winrm get winrm/config
I ran these commands on my Hyper-V nodes and VMM server, while troubleshooting connectivity / permission related errors.