Dave, thank you for the additional information.
I’m working closely with our team on this topic to fix this incorrect information. Since the DisplayPort (DP) outputs on the dock support DP 1.2 only, DP 1.4 is not supported and unfortunately what we’re seeing with the Surface Laptop 3 is expected behavior.
I understand that this incorrect information misled you to purchase a dock with unexpected functionality, so I’d like to help in whatever other way we can.
Currently, our only dock that sounds like it could support what you’re looking for is our UD-ULTC4K dock which can drive up to two displays at 4K 60Hz via DP (plus one 4K 30Hz via HDMI) but please note that this is a USB-C DisplayLink-based docking station. DisplayLink graphics are great for general office or productivity purposes, but we wouldn’t recommend it for gaming or other graphics intensive use. If you’re interested, we’d be glad to send you a courtesy unit for you to try.
Lastly, we’d like to offer you a refund for this purchase, with no return necessary. Please contact us at firstname.lastname@example.org with your Amazon Order ID and we can take the next steps from there.
I’m sorry about all the confusion here, but thanks for giving us a chance to help.