Ready to use vs. powder

Recently, my husband and I try to switch our baby girl over to powder formula instead of using the ready to use. She didn’t seem to like the powder and spit all of it up after every feeding. She doesn’t spit up when we give her the ready to use. Being a first time mom, I am not sure if that is normal. Should we continue to introduce the powder or just stay with the ready to use? Also, it is the same brand of formula so I don’t really understand why she is spitting up one but not the other.