Maybe the behaviour is triggered by displayport cables with pin 20 connected. http://monitorinsider.com/displayport/dp_pin20_controversy.html http://monitorins

Maybe the behaviour is triggered by displayport cables with pin 20 connected. http://monitorinsider.com/displayport/dp_pin20_controversy.html http://monitorinsider.com/displayport/dp_pin20_controversy.h... https://www.dell.com/support/kbdoc/en-us/000132935/the-20th-pin-is-not-wired-on-dell-displayport-cables https://www.dell.com/support/kbdoc/en-us/000132935/the-20th-...