Notebook Hardware and Upgrade Questions

Hi,

I have just purchased the new HP Elite USB-C Dock (Z9R42AA), the one which supports DisplayPort Alt Mode (see product pdf at the bottom of the pdf: http://www8.hp.com/us/en/images/HP_Elite_USB_C_Dock_tcm245_2411508_tcm245_2408746_tcm245-2411508.pdf 😞

3. Supports DisplayPort™ Alt Mode (video, charging and USB 3.1) over the USB-C™ connector. Also compatible with USB Type-C™ Thunderbolt enabled ports.

It's working fine with my HP Elitebook X360 1030 G2, the dock appears on the device manager as "HP USB-C Dock", and everything is recognized (charging, usb devices, ethernet, external monitor).

When connecting my Dell XPS 15 9550, the dock also appears on the device manager as "HP USB-C Dock" but only the charging, usb devices and ethernet are working fine. I cannot display any image on the external monitor.

Both laptops run on the same Windows 10 version, and both are Thunderbolt 3 laptops supporting DisplayPort Alt Mode. Both laptops have the latest versions of Intel display drivers, Realtek audio usb and Realtek network usb drivers.

I also have a Dell Dock (WD15), and on that dock everything is recognized for both the Elitebook X360 and the XPS15, but for some stupid reason HP does not allow charging the Elitebook X360 1030 G2 over the USB-C port with the Dell Dock. This is what forced me to buy a HP Dock in the first place...

So now I have a Dell Dock which works fine for both devices except for the charging on the Elitebook X360, and I have a HP USB-C Dock which works fine for both devices except for the display on an external monitor.

I really want to get rid of one of these Docks so does anyone have any guidance as to how I could troubleshoot the display output issue on the HP USB-C Dock?

Thanks