unfortunately this is the fault of the car seat, most are not designed to support proper posture (particularly newborns) which include keeping the chest elevated and head back so when they fall asleep they don't slouch forward or have their chins down- this obstructs their airways which can cause them to not breathe correctly or at all

When I had my first son I would take a receiving blanket roll it up and put it there for that extra support. Hope it helps! @calirose622mommyluvsu

My daughter does it too and I hate it sadly I haven't t found any fixes except a pool noodle lifting the front of the base up so its more inclined

Move the chest clip a little higher and make sure the straps are nice and snug