Try switching back to starter/grower with oyster shell offered free choice on the side. Or blend some in to your current feed (no sense in wasting money!). The EEs *really* need the higher protein level yet I found all my birds benefited from it when I switched back. It's all I get now. Makes feeding easier, the birds like it and they can lay more eggs and have healthier feathers.
My neighbor was in the same boat with her EEs and she was feeding a high quality layer feed. As soon as she switched back to starter (of the same, high quality brand) her EEs kicked it into gear.
I think the layer formulas are geared toward flocks of mostly Leghorn and Sex Link (like ISA Brown). Some of the new layer feeds I'm seeing are closer to the 20% protein mark, which is better for most backyard birds that aren't bred solely for egg production.
Also, if you have roosters, they'll do much better on the higher protein, lower calcium feed.
Thanks to Junebuggena for the recommendation!