5 month old refusing naps

Recently my 5 month old has been very difficult to put down for naps.

The first issue I have is he’s been waking up earlier, as early as 5am instead of 6am like he used to which is irritating because my oldest wakes at 630. I’ve tried everything to get him to sleep later but he continues to want to be up at 5.

The nap issues is he used to take a morning nap about an hour to two hours after he would wake up but now he will cry and refuse to go to sleep. This is even after trying to nurse him to sleep. Today he’s been awake for over 3 hours and I know this can’t be normal for a baby this young. He showed signs of sleepiness at about 2 hours but then couldn’t fall asleep and then was angry and now wide awake and playing. What am I doing wrong?

Do I just let him stay awake?