Flip him

During the day open windows to let natural light in, have the tv louder, clean/vacuum, Tummy time, play with rattles with baby. Then when your getting close to bed do bath time, lotion, cuddles and turn the noise level down, (not completely cuz you don’t want your baby to get used to just the quite and not be able to sleep if he hears noise). At least that’s what worked for all my kids.

I had the same problem with my baby boy when they are still little/ newborns they just sleep usually whenever they want! Now that he’s older It’s got better but at that age he was the same way. Only thing I can think of is keeping lights on in the morning and having a lot of noise then at night no sounds and pitch dark at certain time.

If you’re not already try to really distinguish between day and night. During the day - lights on, daytime noises, we even had our guy sleep in the living room for naps.

During the night - all lights off, white noise, no talking to or playing with baby, and I’ve heard avoiding eye contact during night feedings helps but idk how true that is.

I personally started a bedtime routine on the first night because I thought it would help relax him and I think it helped tremendously!