He might be over-tired. If you are trying to extend his bedtime, plus he is walking (which can be tiring), he might be over-tired and just waking early because of that. Try and keep his bedtime the same for now, and if he seems tired earlier, put him to bed then. Sometimes putting them to bed earlier will help them sleep later! I don't thing he is ready to get up at 5 in the morning. When my daughter wakes up at that time, I just go in the room and sooth her a little, help her find her pacifier, sometimes give her a little drink of water or milk, and she goes right back to sleep. Try not to get him out of bed at this time. Rub his back or sometime and let him know that it's still nighttime and he needs to sleep a little longer. Then leave the room. Don't go back in unless he's really crying or something. You can also try to make his room darker by hanging darker curtains or something. It could be something outside that wakes him at that time. But try just helping him lay down again and see if that resolves things. But it's pretty normal about this age to start waking in the middle of the night again for a little while. New skills, new teeth, new situations, all make sleeping a little more difficult. Hope this helps! I know how frustrating it is when your kids wake up before you are ready.