This message was posted on behalf of Intel Corporation
I understand you are trying to connect an external monitor via HDMI to Thunderbolt cable. Let me help you on this matter.
I would like to know the Lenovo laptop model number and if possible the graphics driver version, additionally, please attach the graphics report, this is available on the graphics control panel.
See this link for information about the graphics report.
I was able to nmake it work using the HDMI port on my docking station, actually, so I am all set. thanks!