Uniti goes to standby after a while when playing via AppleTV

I have been thoroughly enjoying my Nova, absolutely loving the SQ! All except when I am playing over AppleTV. I have set the auto standby to 5mins. After 5mins of playing it is fine. But perhaps 1/2 hour later (I didn't time this), while in the middle of a song, the unit would suddenly go to standby. Anyone else having this issue or had this issue? I am advised to set auto standby to never as a result. Is auto standby supposed to kick-in after no-user-input for 5mins or after no audio signal for 5mins? Any idea how to solve this problem? Appreciate any idea and advice. Thanks.