Frizzles losing her feathers.

[MOGGIELOGGINSILKIES]

I bought some frizzles at the farm store. Some of my chicks are losing their feathers. They are at 4 weeks old and I've moved them to my outdoor brooder inside my coop. I have a heat lamp on them at night because it still gets pretty cool at night. They've been getting medicated chick starter and probiotics in their water. The other other chicks are doing fine its just a couple of the frizzles. Are they molting or am I doing something wrong?

 

[JacinLarkwell]

That looks like my frazzle girl, Porridge