That's so weird, I'm very sorry you lost them :( I hope the rest do okay. Hopefully someone who is more experienced in situations like this will have advice for you
Can your chicks eat the feed? Some chicks have troubles eating crumbles so young, it's suggested you crush it even further so it's easy to swallow.
I've only incubated once, (currently doing my second) but I don't THINK they would die because of it this long after it happened.
Did either of...