

More than likely it is Doze. https://developer.android.com/training/monitoring-device-state/doze-standby
Supposedly disabling battery restrictions on an app disables Doze, but in practice it doesn’t seem to make much difference.
It has been a thing off and on with Android since Doze was introduced.
It was a mistake, but he had every opportunity to prove he wasn’t guilty of the thing we used as justification to mistakenly deport him. So really, it is kinda his fault. Oh and we can’t get him back. Sorry bye. - ICE probably