Bamboo Rat Snake subspecies cross?

[AlyssaM]

Hello all, I bought a pair of Broad Banded Bamboo Rat Snakes (Oreocryptophis porphyraceus laticinctus) about a year ago. I bred them this spring, and they had two eggs. On went bad right away, the second was mostly collapsed the whole time during incubation despite high humidity. It continued to develop anyway but the hatch date passed and it began to deteriorate more so I opened it up to see the dead fetus. However from the markings, it does not look like a laticinctus baby, which are supposed to have wide yellow bands, not black. I think it looks closest to pulchra. Now unless the baby would have developed yellow instead of black before it hatched, it seems to me they are crosses, or at least not what I thought they were.
So any insight to what is going on? The best I have is that the parents are maybe laticinctus x pulchra but do not have physical features of pulchra? I have attached a photo of the mother and the fetus, I don't have pics of the male on hand but I can get some, he looks the same as the female though.