Monitor (BenQRL2455HM) won't detect a signal when connected using HDMI |[Computer recognizes screen though!]|

[PCBuildingNoob27]

I am using my RL2455HM Monitor from BenQ and am connecting using an HDMI cable directly to my Graphics Card, an MSI GTX 960.
The screen tells me there was no cable connected, but of course there is. The cable sits properly. It worked fine when I connected using a DVI Sub (Single Link). But regardless of the disadvantages of DVI, I need the DVI Header to connect my 2nd Monitor using a VGA Adapter.
The strange thing is, that the Computer recognizes the screen and sets up a multi screen environment for me.

So.. What's the cause here?

 

[PCBuildingNoob27]

I managed to find the cause myself now. It seems like the HDMI Port of my Monitor is damaged. Good that there is a second one I could connect the cable to.