Use the proper cable for the display. Examine the documentation that came with your display and ensure you have the proper cable to connect your display. The Anker PowerExpand is Particular as it offers an HDMI port that supports 4K 60Hz resolutions, the place most are limited to 4K 30Hz. https://usb-c-to-hdmi89764.actoblog.com/26878782/the-hdmi-apple-adapter-diaries