I have a runner who consistently lays shelless eggs, she’s happy and healthy, has access to all the calcium she wants, I’ve done regimens of liquid calcium to no avail, I have personally witnessed the passing of the ”egg” so I know it’s not been eaten. I think the key here is that hers are truly shelless not soft shelled and are tearing inside. If you aren’t offering calcium You should do so, a good all flock will have all they need (except calciu) without mixing any concoction.