exactly right. Otherwise there is some sync (audio ahead of lagging video that increases) issue because the Apple TV 4k (5th generation) is not HDMI 2.1 ...Dolby Atmos. Unless you have all HDMI 2.1 equipment, don’t expect Dolby Atmos to work unless you have an external device. It’s not a matter of performance, but of HDMI standards. ARC in HDMI 2.0 doesn’t officially support Dolby Atmos. eARC in HDMI 2.1 does.