External devices, such as keyboard and mouse cannot work on the monitor if the USB downstream ports on the monitor are not activated. After downstream ports are activated, external devices that use these ports can start working on the monitor. USB downstream ports can be activated in one of the following two ways:
- If the video source is Thunderbolt 3, the USB downstream ports will be activated automatically.
- If not, connect your computer to the USB upstream port with the complimentary USB cable.