Similac NeoSure 22cal side effects?

Hey! Has anyone had any side effects from NeoSure 22 Cal? My twins were born at 32 weeks. They were put on NeoSure 22 Cal from the nicu. My daughter was born with no issues. My son had to go on CPAP for the first week of his life. But ever since I brought my twins home, they have been having issues with the formula. My daughter always sounds congested. She’s not sick nor has she had any issues from birth. She has thick mucus after she drinks the formula. She chokes on the mucus quite regularly. This was brought up at their first month pediatrician appointment. The pediatrician just blew it off like it was nothing. It’s not even that she chokes it’s that she does not breathe. I have to use a snot sucker to suck the mucus out of her mouth for her to be able to get her breath. The formula will come up through her nose three hours after feeding. I keep her elevated at all times, I burp her every ounce, I feed her upright. And nothing seems to work. Someday she goes 10+ times in these fits where she cannot breathe. She’s gasping for air. It’s the scariest thing I have ever had to go through. I’m not sure if anybody has ever experienced this? The pediatrician thinks it’s reflux, but there’s gotta be much more to it. Because this is very very very severe. My son definitely has reflux from it, he’s always gagging and very gassy. He throws up sometimes after eating. But he also is a glutton who wants to eat so fast all the time. We stop with him every ounce as well and burp. I just don’t know what to do anymore. I literally am stressed and I am a mess. It breaks my heart to see her suffer. she is nine weeks old today.