Display Port problem with new HP-monitor (HP EliteDisplay E273m 27)

[Gardis]

I have two brand new monitors from HP (HP EliteDisplay E273m 27) that works together with two HP-computers. I have connected them with a Display Port cabel - the only cable that was included in the package.

But imagine my surprise when the cabel uses the "20th pin" and feed the computers with power!!!

If I unplug the power cord from the computer, the LED lights are still lit and to turn off these the cord must also be removed from the monitor. How is it possible for brand new products?

The fact that Display Port cables feed power on the 20 pin is a well-known problem and therefore they should not be activated by the manufacture according to the statements I read.

Does anyone know something or have a solution?

PS ...

if I use a HDMI cable the screens start to flicker" instead and this problem does not exist with the Display Port. Now it's the power instead... In the manual for EliteDisplay the Display Port socket is recommended. Maybe HP has sent a junk DP-cable? The graphics card is Nvidia.

//Gardis

UPDATE #1

The official Display Port FAQ say the following:

Q: Why isn’t there a wire on pin 20 (POWER) on the standard external DisplayPort cables?

A: The reason power isn’t included in standard cables is because both source and sink devices are designed to provide power. Captive, attached cables often include the power wire. If it is desired, for example, that a particular source device utilize the power available from the mating sink device, then that Source device could include an attached or dedicated cable that carries the DisplayPort power signal. Same could be applied to a sink device.

SO WHY HAS HP THIS CABLE WITH PIN 20 ACTIVATED WITH BRAND NEW MONITORS?  

UPDATE #2

The Problem from Monitor Insider:

The problem with this arrangment is that one should never ever connect the DP_PWR of the source to the DP_PWR of the sink: it's impossible for both pins to have exactly the same voltage, so connecting them together would effectively result in a short circuit condition. In addition, if, your GPU is powered off, while your monitor is powered on, you get a problem that's commonly called 'backdrive': a sneaker path that feeds electrical compoonents in the GPU even though nothing is supposed to have power. This can result in your GPU behaving erratically when trying to power up. In some cases, it can even damage the GPU. This is why regular DP cables should never have a wire between pin 20 of boths sides of the cable.

AGAIN -SO WHY HAS HP THIS CABLE WITH PIN 20 ACTIVATED WITH BRAND NEW MONITORS?  

UPDATE #3

CONFIRMATION!!!

 I can now confirm that the display port cabel provides power back to the computer.  We have changed cabel today to a more professional one and the "backdrive" problem disappeared. We have now GPU problems on one computer.

//Gardis

[Gardis]

This cabel helped us:

https://www.liontech.se/club-3d-club3d-displayport-kabel-14-hbr3/cat-p/c/p9825132

[OMNIISGITGuy]

Thank you for this. We received some HP EliteDisplay E233's and could not get them working with an HP slimline docking station. We had spare display port cables from an Iiyama and these worked perfectly first time. Thanks again.