6 month old slept through the night until now

Hi! We’re getting a little desperate and are seeking advice. Our baby slept perfectly through the night starting around 6-8 weeks (we got lucky and didn’t do anything to make that happen). He’s always been fine with naps, but not an amazing napper. Right when he turned 6 months he’s stopped sleeping through the night and wakes about every 3 hours. We aim for an 8:00 bedtime but we have to wake him by 6:00 to get ready for daycare. He started daycare when he was 4 months and was fine with napping there and it didn’t seem to effect his evening sleep.

We’re not sure what to do since we can’t control his daytime naps anymore. The only thing that will get him back to sleep during the night is nursing. Where should we even start???