When installing a new driver, the firmware of the connected USB monitor might need to update. When this happens, on the screen of the USB monitor usually stays black for a prolonged period of time.
Starting with DisplayLink driver for Windows 9.4 M0 (currently in Beta) and macOS 5.2.4 driver or the DisplayLink Manager app, if the firmware is updating, you will see the symbol below on your USB monitor.
If you are on an earlier version of the driver, please be patient and allow your monitor at least a couple of minutes to light up. Thank you.