we had a couple of mornings of 5am wake ups and then quite a few nights where she would wake at say 3am and refuse to go back to sleep until 5am
It could just be a phase he is going through, hopefully he stops it soon if it is! You could probably try only giving one sleep a day, but he might just get overtired instead?

Good luck hun, for your sake I hope he starts waking at a decent hour soon!