Hiya I've had this problem for 3/4 nights - he hasn't been crying though just like awake and happy not wanting to sleep at all! I brought his last nap earlier yesterday - finished at 4.20 and did bed time 19.30 and it seemed to help. But also that could be a coincidence! A lot of my mum friends who have older babies said their babies went through this phase. Things that helped were tiring baby out during the day a lot, reducing night time sleep, making sure to have a long wake window of like 3 hours before bed... It might be that by the time it gets to 4/5am they've "maxed out" on their sleep for 24 hours ... Xx
Apparently at this age they have a drop in sleep needs eg they drop a nap etc so maybe it's that
As I am typing now, am in the same situation. My baby boy of 6months is sitting on my lap after he’s had his feed around 4am and I have been struggling to get him back to bed but no avail. He used to go to bed at 9pm and wakes up at 2am for a feed but recently he wakes up at 4/5am for a feed and after I have to sit down like 2hrs to get him back to bed again. Sorry but I really don’t know any tricks that works pls mamas here any tips to help us thank you ☺️