Boob rejection

Baby is 6w4d and she’s been rejecting one boob only at night time. She legit knows the moment I position her and she’ll start yelling her guts off. I pick her up and calm her down and try again but nothing. So I tried to put her on the other breast that she just feed from and she’ll take it easily. However, like I mentioned, this out happens at one of the night time feeds and the rest of her feeds at night are like normal. Would this be a growth spurt or what would this be? And it’s always the same boob side that she rejects at that specific feed.