Let $X$ and $Y$ be generic cubic and quadric hyoersurfaces in $\mathbb{CP}^4$. Let $Z$ be their intersection, which is a K3 surface. Then by adjunction formula, $N_{Z/X}=-K_X|_Z$ and $N_{Z/Y}=-K_Y|_Z$ are both ample. On the other hand, Kawamata-Namikawa deformation theorem claims that $X\cup Y$ is smoothable iff $N_{Z/X}\otimes N_{Z/Y} \cong \mathcal{O}_Z$. This should hold in our case because $X\cup Y$ is smoothable to a quintic threefold, but it conflicts with the above ampleness. So it seems I misunderstand something. Could anyone point it out?

Let $X$ and $Y$ be generic cubic and quadric hypersurfaces in $\mathbb{CP}^4$. Let $Z$ be their intersection, which is a K3 surface. Then by adjunction formula, $N_{Z/X}=-K_X|_Z$ and $N_{Z/Y}=-K_Y|_Z$ are both ample. On the other hand, Kawamata-Namikawa deformation theorem claims that $X\cup Y$ is smoothable iff $N_{Z/X}\otimes N_{Z/Y} \cong \mathcal{O}_Z$. This should hold in our case because $X\cup Y$ is smoothable to a quintic threefold, but it conflicts with the above ampleness. So it seems I misunderstand something. Could anyone point it out?