Why is my 2 year old suddenly not sleeping? Nothing has changed in his routine, but he has been…

Why is my 2 year old suddenly not sleeping? Nothing has changed in his routine, but he has been waking up earlier and earlier everyday. He used to sleep til 7:30 but then it moved to 7:00, then 6:45 then 6:20 and now today he was up at 5:40 😩 His bedtime has not changed and I cannot change it because we have a schedule and I cannot move it up by 2 hours.

Today he napped for 50 minutes even though he was up so early. This has been going on for a week now.