If the root stock fails to push a few leaves the root stock is likely not very healthy/active. I have realized that every failed graft that I have necropsied this spring has been the result of a root stock that has shown no root growth or very, very little root growth. I would leave it and see if the root stock eventually sends out a bud. If so you can regraft it at some point.
I have pears that show all those symptoms each spring. Most times the grow out of it. Generally it is environmental stress (heat, wind, both). Make sure your not over or under watering.