Can't get a dual monitor setup with Dell dock station

[AlbanRampon]

Hello,

Thank you for the detailed description.
I have never seen an HDMI to DisplayPort cable. I know the other way and it's quite common. These cables don't work both ways.

Would you please be able to check that the cable is transforming HDMI signals to DisplayPort? If that's confirmed, I'd like to get the link to that cable to understand how manufacturer state they work.

I believe that's the monitor reference I use at the office (3 of them). When I was using a Dell D3100, 2 were corrected via an HDMI to DVI cable.

Kind regards,
Alban