the display ports are not working on my clients d6000 dock
 

Hello, I have a client that is trying to use the d6000 doc to run multiple screens. He is using a dell latitude 5411. Everything is connected and he has 3 monitors. The monitor connected to the HDMI is working fine. The monitors that are connected to the display ports will not show up. We have updated all the drivers needed, rebooted the laptop but they will not show up.