jerrysgirl1984
Chirping
Yes they have been eating the all flock sometimes the feather fixer they mainly free range and then they come for treats and to eat from the hanging feeders in the afternoon or evening the treats I give are the upper cut and the Bang cockI'm not familiar with uppercut or bang cock. Do you have photos of those products.
11 week old are eating all flock right? Not layer feed.
With that many birds, if you lose another, then sending the body for necropsy would give you the best answers. This will help you figure out what changes, treatment(s) are needed, if any.
https://www.metzerfarms.com/poultry-labs.html
I attached pictures of the labels