Sleep advice?!

My 6 month old keep waking up at 3am for hours. He usually falls back asleep at 5 ish for 40 mins then once he’s back down wakes up at 7. I don’t speak or turn on any lights etc he just seems to be wide awake. Chatting, playing and rolling etc.

Any advice how to stop this?? His bed time isn’t very consistent but his naps vary so much that I don’t get how to have the same bed time every night 😭