Probably some "internal magic", but are you sure there is no timed "ON" function set?
Try putting the remote in another room. If that does not work, try unplugging the bush button panel.
I once had a Grundig that often switched itself on in the afternoon. It was in the middle room, "on soak", and I kept it there trying to puzzle out what was the problem. In fact I finally concluded it was the sun, behind the trees at the top of a nearby slope that were waving in the wind and confusing the remote control decoding panel. Codes were much simpler back then.
Les.
