For example, FRL 6 gives you the full 48, whereas you're only getting 40 with FRL 5 and 32 with FRL 4. All a bit geeky I know, but the problem I'm pointing out here is not all HDMI 2.1 ports are ...
The HDMI interface is electrically identical and compatible with the video-only DVI interface, which came first. For example, if a cable box or PC has DVI out, but the TV or monitor only has HDMI ...