I have a Dell Latitude E7450 laptop with a E-Port Plus II port replicator connected to two external monitors using DisplayPort which will not output to multiple monitors.
I have another Dell model and when placed on the port replicator with two external monitors connected, booting into BIOS/UEFI the screen is cloned onto each monitor. However, when doing the same with a brand new Dell Latitude E7450 only one screen is active - the other is off. Within Windows itself, I can only have 1 monitor connected to the port replicator. If I undock, I can run 3 monitors independently indicating an issue with the dock rather than a hardware limitation with the laptop itself.
I believe the above tests eliminates the OS or driver issue and highlights a compatibility issue between the new Dell Latitude E7450 laptop and E-Port Plus II port replicator. I have tried this on 2 separate machines with the same results. I have also updated both the graphics drivers (Version 10.18.14.4170, A16) and the BIOS (Version A04) to the latest releases. I have also tried using DVI cables as well as swapping out the port replicators. Nothing works. In Windows 8.1 itself, it actually shows as two monitors active, but one is not on. If I swap out the monitors to a different brand, I get the same result.
Is there a BIOS/UEFI setting I need to change? Is there a newer port replicator or update I need?