Frozen milk

I was so proud of my freezer stash. About 400oz of frozen milk (I’m 3 months PP)... I donated half of it to a non for profit to help preemies, and kept half of it for my baby so I can eventually stop pumping.

This weekend we were going away and I used frozen milk for the first time. My baby hated it and absolutely refused to drink it. I tried it one more time with a bag that I froze this month and same thing happened. Anyone know why? Seems like I’m gonna have to donate it all... and keep pumping.