Newborn will not sleep flat on back

Megan

So my little one is 4 days old and we have a Halo bassinet set up at our bedside. We love the bassinet but our little guy rolls onto his side like a little overstuffed taco 🌮 everytime we set him in it and he hates sleeping flat. He wakes up immediately after I just had him all snuggled and milk drunk because he just seems uncomfortable. We have tried different swaddles, not swaddling him at all and still he goes onto his side and seems uncomfortable in the bassinet overall. When he’s napping in his bouncer on top of his pack n play during the day, which is at a slight angle, he sleeps beautifully on his back and he sleeps without fussing for 2.5 hours at a time. He also spits up less and seems to have less gas. I’m half tempted to let him sleep in this at night next to our bed, but I’m aware a bouncer isn’t considered safe sleep. But on the other hand neither is side sleeping, which is feeling unavoidable in his bassinet. We have an owlet monitor as well as an extra safety measure. So I’m glad we can at least utilize that. I’m just so torn on how to get him comfy and still be safe between feeds at night so I can sleep knowing he’s alright. Anyone have insight?