HDMI port unable to function when docking E7450

Hello,

I having this problem with my 3-monitor setup on Dell E7450 notebook. This is the express service tag: .

When my notebook connected to the docking station, my HDMI connected monitor will not function while my connected VGA monitor through docking is still working. If I undock, the HDMI connected monitor will working, so I know this is not related to notebook HDMI port issue.

I looking for a solution to this, how to connect the third monitor with HDMI-cable, while VGA-connected monitor and notebook display monitor is working.

Alternatively, maybe just to get some confirmation is this something limitation due to notebook display card problem?