Supplementing

Just had our 4 month checkup with the pediatrician and my baby girl isn’t gaining enough weight from nursing 😞 doctor recommended supplementing, she said to nurse her then top her off with 2-3oz of formula 2-3 times a day, going back in 1 month for weight check. We’ve been using Enfamil but that seems to be affecting my daughters sleep at night. She falls asleep for 10 minutes then wakes up and is off and off throughout the night. Anyone have the same experience with Enfamil? Have you switched to Similac and have a better experience?