Hey mama,
Perhaps this could have to do with the fact that your LO’s circadian rhythm isn’t fully developed yet. Babies usually spend a lot more time in active sleep (REM) and this is where they retain a lot of muscle tone. And they may move or even cry. It takes a while before they can move into transitional and then quiet sleep. You can help move baby along by taking cues from her developmental patterns -
1) quieten down the house towards the evening and keep the house active and noisy in the day
2) try doing some calming things (like singing a lullaby or reading a story) during bedtime routine
3) involve baby in your daily routine
I thought this article was quite useful:
https://parentingscience.com/baby-sleep-patterns/
Again, I’d like to point out that we don’t aim to train baby to sleeping longer but to guide and facilitate baby alongside her natural developmental patterns and stages.
You can also find out more from Anahita Bahtia who is a professional and qualified sleep consultant.
Hope this helps!