At a minimum, eARC requires that both an audio device and its connected HDMI port support HDMI 2.1. If you're unsure, check your audio gear's specifications, and connect it to the port marked "eARC" ...
I’ve been working with computers for ages, starting with a multi-year stint in purchasing for a major IBM reseller in New York City before eventually landing at PCMag (back when it was still in print ...