69DK7 can't extend the 5K monitor?
For 5K support, you must connect both Display Port connectors to one 5K display monitor. That is to say, two DisplayPort 1.2 cables must be connected from our dock to a single 5K display to support 5K@60Hz.
DisplayPort equipped monitors and DisplayPort cable must support DisplayPort 1.2 specification in order to support 4K@60Hz. The resolution will be limited to 4K@30Hz if the display or cable does not support DisplayPort 1.2 specifications.Update Time：17/07/2018