
I wonder if her demeanor is in fact a breed thing. Certainly most modern UK breeders rear their litters in the home with lots of handling but it was not always so, our first dog, a Cocker Spaniel was reared in outside kennels as was common then, other than feeding and cleaning I don't think the breeder spend a great deal of time with them and she did not come to us until 12 weeks old and yet, like most Cockers these days, if she could have unzipped our skins and popped herself inside she would have done so. There are not too many Griffon owners on this board that I am aware of :) but some do have, perhaps, similar hunting breeds and I think they may confirm that they are often fairly aloof in character and are often "difficult" with the recall.
Hopefully someone with experience within the hound types will be able to offer some advise on how you might improve things on the recall front.