Dell Latitude E7440 with E-port docking station doesn't detect monitor ( 2560x1440) via displayport. The only way to get the docking/computer to detect the attached display is to remove the powercable from display and power-on again.
Windows 7 installation, all drivers updated, bios A15, HDMI works fine but is limited to 1920x1200.
We have several computers With the same problem at work.