cannot connect vm in hyperV

[wiwengweng]

Hi, my env is windows 10 with HyperV. I test freeRDP-webcontent and wfreeRDP. Both can connect to the host, but wfreeRDP cannot connect to vm, while webcontent works.
in wfreerdp I exec this command:
C:\FreeRDP>wfreerdp.exe /v:10.1.xx.xx /u:administrator /p:xxxxxxxx /vmconnect:3a56d4cc-75f8-4135-962b-6f9be5a50c36
and this vmid works in web content. I also try to include '/port:2179', but still not working.
Can you give me some hints? Thanks.