Control Center supports HDMI 2.0/HDCP 2.2 and is also backwards compatible with all older versions of HDMI.
Please note that not all HDMI cables are created equal. The HDMI cables you were using for your 1080p shows will very likely not work well for all 4K bandwidths. HDMI 2.0b 18gbps rated cables are needed in order to reliably display 4K resolutions and HDR color on TVs that support those modes. Using an HDMI cable with the wrong rating will likely have negative effects on video quality including flicker and black screens. HDMI cable length can also impact performance as the signal and timing will degrade more over longer cables.
In order to successfully display 4K resolutions and HDR color, all video content, components, and cables in the video path must also meet the above specs. This includes source devices, TV, AVR/Soundbar, and HDMI cables. For the best audio/video experience, we recommend using relatively short, high quality, HDMI 2.0b 18gbps cables that are also HDCP 2.2 compatible. This should allow you to watch 4K/HDR content on your 4K/HDR entertainment system glitch-free.