DisplayPort won't work on USB-C dock

I have the USB-C Triple Display 4k Docking Station. It is connected to an HP laptop with Windows 10 Professional. I installed the most recent drivers from your site, and connected everything to the dock.

The issue is that the monitor connected to the DisplayPort on the docking station doesn’t display an image. Both DisplayPorts do the same thing. The light on the Viewsonic monitor is blue, which means it sees a signal. But the image is black (image 1).

If I plug the display directly into the laptop via DisplayPort, it works. Here’s the weird part. When I reboot the laptop, it works, but only on the restart screen. See in (image 2) that it displays the Windows 10 restart screen. When the laptop reboots, I get a black screen again.

Any ideas?

!](https://d2r1vs3d9006ap.cloudfront.net/s3_images/1703020/image1_inline.png?1518472474)](https://d2r1vs3d9006ap.cloudfront.net/s3_images/1703020/image1.png?1518472474) !](https://d2r1vs3d9006ap.cloudfront.net/s3_images/1703021/image2_inline.png?1518472485)](https://d2r1vs3d9006ap.cloudfront.net/s3_images/1703021/image2.png?1518472485)