Second stretch of the night is the worst

My 8 week old has a good first stretch of the night, but her second stretch always seems to be terrible. After her first stretch, she’ll need to eat, we burp her, hold her upright for 15 minutes, and then she’ll go to bed. (I say that simply but sometimes it’ll take her an hour or even two to get back to sleep… bc sometimes she’ll then make a massive poop after she eats).

But no matter what, around 30 minutes after she goes to bed, she’ll start waking. She’ll kick and groan, and then eventually will open her eyes. We’ll increase the sound machine, then we’ll add a hand to her chest and usually that will help her fall asleep.

In the beginning, we used to think that we needed to do this just because she was still learning her digestive system and she as always grunting, but now, she just falls asleep so quickly after we put a hand to her chest.

Am I creating a habit for her that she always then wakes up 30 min after she sleeps? Or is this just normal 8 week behavior? It’s driving me and my husband crazy bc the first stretch usually goes so well, but no matter what, the second half of the night is such a battle. (She falls asleep quickly after we put a hand to her chest, but then when we go back to bed, she will wake up again 15-20 min later and want to be soothed). Is this just normal 8 week old behavior? Or is there a way to avoid this?

We follow her wake windows during the day and also her naps are pretty regular in length.