It depends on whether your hydrogenated graphene structure is hexagonal or not, i.e., it depends on how you did hydrogenation. In the Builder, you can choose the lattice type in the Bulk Tools -> Lattice Parameters. For some reason, the lattice type for your structure was set to Unit Cell, i.e., no symmetry is assumed. It might also be because you are using a supercell, not a primitive cell of graphene, for hydrogeneted graphene.
