Problems with a skin formed. White Buffalo (Red Dead Redemption 2)

In short, I found a Buffalo killed, skinned. Got the horn, the skin is also put on the horse, went to the hunter, and he does not want to buy a skin of the Buffalo, or more precisely the skin is on the saddle and in the sell menu is not showing at all. Then I seamobile to the legendary skin automatically type sold out well, you know how it is. But still, the skin is just gone, and I could not do the hood from the skins of Buffalo. Does anyone know why? This is a bug or feature
Somebody faced?
And if they can re-kill?
P. s the guide is an animal, not shown, and on the map it is crossed out, as if killed.