You stated in your first post that you noticed the symptoms at night while the birds were roosting.
It's possible there are ammonia fumes from soiled bedding that's causing the symptoms and/or inadequate ventilation in the coop.
Both of these issues can be corrected.
Right now there in a open coop plan in process of finishing winter coop. But I notice it to all day long. That’s just the first time I actually seen them do it. 4 days ago but I noticed the white poop about 2 days before most my hens have it down there but. I need to bath them but idk if that’s part of issue or not.