Hello, I recently bought a HDMI 2.0 adapter, with HDMI as Output and USB C as input.
Picture of my devices; https://i.imgur.com/VAcA0hF.jpg
When I put the adapter HDMI into my monitor, then put the USB C cable into it, and with USB C cable end, nothing happens at all. It usually works for other types of HDMI, just no picture coming here.
Are you sure the USB-C cable is capable of video and not only data?
Have you tried an active USB-C to HDMI adapter cable instead?
Some laptops also boost the power output on the ports when the charger is connected. Have you tried it while having the charging cable connected as well?