Livestock is hard.
To make a long story short, I lost another molting chicken today and because she passed in the same manner that my other molting chicken passed, I opened her up. Thankfully, no organ damage but she was TINY. The only physical signs she had were that she was small and she was molting. I didn't realize that you need to swap to a higher protein feed and/or supplement with high protein treats. For now, for molt, I have them on a 18% protein feed and I'm gonna hit them with BSF and sunflower seeds as treats now.
I messed up and two of my birds are now dead. I feel awful. I can only learn and now I know, going forward, more protein as soon as they start molting. I'm also not going to stick with the brand of feed I was using. I suspect store-brand not being as good of quality and when I opened the new feed, it smelled better.