Yeah they do. I'm assuming they're what breeders/show folk call white "faults". I've heard of a marking called "collared", but that should be an expression of the mottled gene, which cannot be carried. Since neither of your parents are mottled and no pups show more white than they do, I'm assuming that these are just uncommon white markings, more like the ones more commonly found on feet, stomachs, and chins. It does make them very unique, though!