Breastfeeding only 5-10 minutes

My LO is 7 weeks. During the first week she would nurse about 20-40 minutes per session every 2 hours unless she clustered then more frequently. Once she hit about 3 weeks, she would only nurse tops for 15 minutes and only in one boob. Then will eat again with the hour for 10 or so minutes on the other. As she’s gotten older, during the day she only nurses 5-10 minutes total every 30 minutes to an hour while she’s awake. She’ll typically snack 4 times per awake time. I can’t get her to eat longer to be satisfied longer :\

She cluster feeds and fusses horribly nightly from 7 to 9:30 but then sleeps for 4 hours. From there on out she’s stirs every hour to 2 hours to nurse for maybe 5 minutes but won’t wake up enough to eat longer to sleep longer after 1:30am. Even doing a diaper change will only stir her enough to almost make it to 8 minutes.

Any advice or is this normal? I thought babies were supposed to nurse 20-30 minutes per session. It’s not affecting her weight, she’s gain over 5 lbs in 7 weeks.