Apple cinema display stopped working on upgrade to Mojave (iMac Pro)

My recently purchased iMac Pro died (running High Sierra) Apple replaced with new iMac Pro, now running Mojave.

Now my Apple cinema display has completely stopped working. I'm using a mini display port to USB-C adapter to get it into iMac Pro. Exactly as I did flawlessly with my previous iMac Pro.

Any ideas would be much appriciated!

Thanks.