cannot get 4k on two monitors with HP EliteBook 840 G6 + USB-C dock G5

[mmir]

Hi HP Community,

I have two Samsung U28R55 monitors each supporting 4K resolution at 3840 x 2160 @ 60Hz (supports HDMI 2.0 and DP1.2) connected to a USB-C G5 docking which in turns connects to the EliteBook 840 G6. With this setup I am unable to get 4K resolution when both monitors connect using DP1.4 cables neither when one monitor connects with HDMI and the other with DP nor when both connect using DP. With this setup the max i get is 1920x1080 at 60Hz on both monitors. I was convinced the dock supported dual monitor at 4k. When i connect one monitor to the dock and the other directly to the computer i do get 4k on both displays so i guess the computer supports it.

Any idea what is wrong and how can it be fixed?

Thank you in advance

[banhien]

@mmir 

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Regards

[mmir]

Hi

.@Banhien

Thank you so much for your prompt response, however, i am not sure i understood it. I am not using the computer built in monitor, just two external monitors. Shouldn't this be a Two Display set up?

The cables i have support 8k I believe (DP1.4), or at least were advertised as supporting it. When i connect both monitors using this cable i can only get 1080p resolutions on both monitors. The built-in laptop monitor is off.

Thank you in advance for your time.