This typically occurs because the cable being used to connect the dock to the system is not a Thunderbolt cable, but rather a USB-C cable. The white cable included with MacBook Pro laptops for charging is a USB-C cable, not Thunderbolt. In fact the included cable doesn't even support USB 3 data - it is a charge and USB 2.0 data only cable.

Please use only the Thunderbolt cable we include in the box with our Thunderbolt docking stations to connect it to your system. For additional information about this issue, please see this demonstration video -> https://youtu.be/YJKKOjFc6zE

If you have any questions please feel free to contact us at support@plugable.com and we'll be happy to help!