Yes the soft shells are a worry and could indicate an underlying infection. I have had so many problems with my white and KC girls, it breaks my heart. I have found that the rare breeds are best for only laying seasonally, my Buff Orpington’s never have issues and they are ten years old now... although two have changed sex now! I can highly recommend them. Sweetest nature too.
They laying season has been all over the place this year with the weird weather!