Hi Alex,
I connect my apple tv in this manner
Apple TV - Denon AV8500 Pre Tuner - Sony WD800 TV.
(this problem occurs, Both in Apple TV's Music app as well as from my iphone 7 Plus (that streams Songs from my local DLNA))
When the Tv is on, Apple tv plays very normal, if i switch off the TV suddenly song streaming lagging instantly.
FYI, Previously I used Apple TV 3, in that i never had a problem with my Optical Digital out, but in same Apple TV, I had this same experience. in that ATV3, i just ignored this issue because i simply alternate my audio out with optical rather HDMI.
This how i am helpless, Plesae guide me with a solution.
Regards,
Tony Felix.F
India