Over a couple of days, I found that the G3 would be waking up, without any known activity by myself. One incident, I had been playing recorded mp3's, put the player in pause, put the phone in standby, and drove to a gas station to fill up. Shortly before arrival, the phone had woken up, and resumed playing the last mp3 file. (weird).
I had gone from KitKat to Lollipop to Marshmallow, never needing to do a Factory reset. I decided to do that.
Used the LG backup to record to my memory card, and knew also, that Google backup would have other things covered.
Did factory reset, let google do its restore, then did a LG restore. Will monitor over a couple days to determine how the G3 did,