iMac Pro adaptor to HDMI as second monitor?

[Craig Seeman]

iMac Pro adaptor to HDMI as second monitor?
Attempting to add second monitor to my setup (Dell U2713hm or HP L2745w) via HDMI.
I attempted to use TB3/USB-C to HDMI cable known compatible with new MBP but it does not work with iMac Pro.
Computer doesn’t acknowledge anything is connected.

B&H recommended this which did not work
https://ezq.com/usb-c-hdmi-cable-60hz-2m.html

I posted on Apple’s Community Forum and the only recommendation was Apple’s
USB-C Digital AV Multiport Adapter
https://www.apple.com/shop/product/MJ1K2AM/A/usb-c-digital-av-multiport-adapter?fnode=85&fs=f%3D27imacpro_2017%26fh%3D459d%252B499c
Which is not all that great given it’s limited to 30Hz at 4K.

Seems others are having issues finding a viable solution.
https://discussions.apple.com/thread/8262750

So perhaps there’s a serious compatibility issue.

Can anyone CONFIRM a TB3/USB-C to HDMI solution that is 60Hz?

[Craig Seeman]

Apparently I’m alone in this or everyone is using Display Port to USB-C.

In any case I found I had to reverse the cable and push very hard to snap in.
This is not something I needed to do using my Apple TB3 cable which doesn’t seem to “lock” like the USB-C cable does. It might just be the specific manufacture’s cable.