I wonder if its an app issue. This morning after 30 minutes of taking off charger, and not being used, I finally opened phone and it was down to 97%. Never has done that. I had the Roku app still open from the night before (although suspended) so force closed it and charged back up. Been fine every since. It was several hours later and was still on 100% (on stdby of course). I typically close that app after using it because it can run audio when in background. So wondering if other apps similar may be the cause of this random drain that happens out of the blue.