I did not feed mine 24/7, but I did find that they were a bit desperate for water no matter how many times I filled it up. Finally I started soaking the feed to the consistency of good sand castle. They did much better. They eat a lot, a lot of dry feed is dehydrating.
I did not have 100, but I did not have a huge brooder either, and at one week of age, mine went out to their coop. No electricity, no added heat but with huddle boxes they did fine. When they eat that much, they put off a lot of heat!
I feed mine twice a day, about enough to keep them eating for 30 minutes.
Just butchered mine today. Whew, got it done.
It is not uncommon to have some losses. Hope you get it figured out.
Mrs K