It’s because it’s so watery. Get yourself some carobel (Amazon) thickens it up x
Ours was the same, but he was prescribed omeprazole at the same time. The great volumes of spit up (like a fountain most times) cleared up in about 5/6 weeks
my son has been on it since 2 months old he’s now 6 months and at first he was still quite sick on it but the sick was clear he’s also on omeprazole for reflux and now 4 months later he’s absolutely fine on it so maybe give it a bit of time to work in her system
I had the same thing with my little one, she was put on gaviscon which didn’t make much difference. She’s since changed formula twice and has settle really well with neocate.