Congratulations on the baby, not sure if it’s your first, but if it is…don’t ever brag to anybody that your baby is a good sleeper. It backfires lol.
You mentioned your series of O’s got better on the right side of the machine, check and make sure both of your Y stepper motors are plugged in and powering up, and double check that their pulleys are lined up on the shaft flat, and set screws are indeed tight. Seems like this issue could be caused if one side of the gantry is dragging a bit.