XPS 13-9370, S2316H, USB Type-C to HDMI cable not working

I have the following situation:

I am trying to connect a Dell S2316H (HDMI) directly to the USB Type-C port on my Dell XPS 13-9370. 

I have bought a USB Type-C to HDMI cable especially for that. It does not work, the XPS 13-9370 simply does not see the S2316H. And then the S2316H enters into power saving mode, as if nothing was connected to it. 

Important mentions:

- I have successfully connected the two (XPS 13-9370 & S2316H) via a USB Type-C to HDMI adapter!
- The cable is working fine. I have connected a USB Type-C smartphone directly to the S2316H. 
- Did all the Windows and Dell updates.

Any ideas?

Thanks