How to get baby to wake up later

My 5 month old wakes up around 5:30 for the day, I consider 6am a lie in now, as it’s rare he will wake that late.

Until recently 8pm was his bedtime. So 10 hours night sleep. I was worried this wasn’t enough so moved his bedtime to 6pm, however now he will wake at around 12/1am and be awake for over an hour, not hungry, not in pain, just wide awake.

Should I move his bedtime back to 8pm, even tho he wakes at 5:30? This would mean a lot of naps, maybe even 5. Or should I continue with 6pm bedtime even tho it means he’s wide awake in the middle of the night?