The new StarTech 4-in-1 Travel A/V Adapter with USB-C can be used if you need to connect your USB Type-C devices to a TV or display. Unfortunately, the HTC 10 is not able to display anything when using the StarTech 4-in-1 Travel A/V Adapter with USB-C to connect to the LG Thunderbolt Monitor 34UM95 over HDMI.
Here are the following devices used in the setup.
1. LG Thunderbolt Monitor 34UM95
2. StarTech 4-in-1 Travel A/V Adapter with USB-C
4. HDMI cable
Connect the HDMI cable between the LG Thunderbolt Monitor 34UM95 and the StarTech 4-in-1 Travel A/V Adapter with USB-C.
You can then pull out the USB-C cable from the side of the StarTech 4-in-1 Travel A/V Adapter with USB-C and connect to the USB Type-C interface to the HTC 10. At this point the HTC 10 is using DisplayPort over USB Type-C to connect to the StarTech 4-in-1 Travel A/V Adapter with USB-C.
Once connected the HTC 10 will detect the USB device and external display connection .
The LG Thunderbolt Monitor 34UM95 is able to detect the HDMI signal from the StarTech 4-in-1 Travel A/V Adapter with USB-C for a second but unfortunately it then stops displaying anything.
Note that with you use the LG 27 inch Class Ultra HD IPS 4K 27UD88-W Monitor instead of the LG Thunderbolt Monitor 34UM95 to connect using HDMI to the StarTech 4-in-1 Travel A/V Adapter with USB-C, the HTC 10 display is able to mirror onto the monitor.