I have a Cable Matters USB C to Dual 4K DisplayPort Hub and a MacBook Pro 2016 (No touchbar). I am using Windows on Bootcamp.
The hub works fine with a DisplayPort to VGA adaptor, but it doesn't work with a DisplayPort to HDMI adaptor or cable. I have tried the hub on both MacOS and Windows 10 but the external HDMI display detects power (an icon appears showing there is something connected) but does not detect any signal.
I have updated the graphics drivers, reinstalled the USB C drivers and reinstalled Windows but nothing worked. The hub and HDMI display work with a HP laptop with similar Intel integrated graphics.
Does it not work because the DisplayPort to HDMI is passive?