This is because the USB-C port of your laptop is not full-featured (i.e. it can charge, transmit data, and display video at the same time). Usually, many laptops are equipped with HDMI or VGA, and the USB-C port does not have full functions but only charging, or only charging and data transmission. If this is the case, the USB-C interface cannot use the expansion dock with HDMI and VGA to achieve the video expansion function.
Please make sure that the USB-C port of your laptop supports Power Delivery, DisplayPort, and Data transmission, you can easily find the detailed specifications of the port on the user manual of the laptop, or consult the seller Whether your laptop model is compatible with our docking station.
In most situations, if there is a DP or Thunderbolt icon next to the USB-C port, it means your laptop can fully work with our USB-C Hub.