My setup is as follows:
MacBook Pro (13-inch, 2017, Four Thunderbolt 3 Ports) running macOS Catalina
Dell U2720Q monitor
This monitor supports HDCP (DP 1.4 - HDCP 1.4/HDCP 2.2 and HDMI 2.0 -HDCP 1.4/HDCP 2.2)
Monitor is connected to MacBook Pro using CableMatters USB-C to DisplayPort Cable...
Hey everyone!
It is known that Netflix 4k support is on Kaby Lake processors only.
In addition to running on Windows 10 Edge browser only as well.
http://www.theverge.com/2016/11/21/13703152/netflix-4k-pc-windows-support
All in all, it is all due to Kaby Lake having HDCP 2.2 DRM hardware...