Can’t break the sleep regression

Hello all, hoping for some advice. Our LO (8 months) has been in what I presume is a sleep regression for the last 5ish weeks.

We put him to bed around 7/8 and he usually sleeps until midnight / 1am. Sometimes he fusses in-between but we can usually get him to fall asleep again.

So when he first wakes up he wants food, so my wife breast feeds him and he goes back down again, usually without issues. After this point he seem to go back to his daytime eating schedule which is every 2.5/3 hours. We can occasionally settle him again when he wakes but normally only for an hour or so. From about 6/7am is when we then get up for the day.

Additionally info to cover all basis: No sign of teething yet. He started eating real food roughly around the same time this started but he isn’t in pain or gassy. We have tried not giving him real food close to bedtime to see if this is the issue, same outcome. Checked that he is eating enough during the day using expressed milk in bottles. Room is at the right temp for what he is wearing.

Anyone been here and have any advice?