Three of the seven I grow here do not have buds. I am likely south of you at my home between Allentown and Philadelphia.

Have you been cutting them back in the spring? Take a picture when they bloom and maybe someone can identify your plants. They will then be able to tell you when to prune and what to expect.

If the plants look healthy, I wouldn't worry. Be patient, they will come.

When did it bloom the last two summers? If it really blooms in the summer, I am not surprised that you don't have buds yet. What your neighbors' clematis are doing right now is immaterial to whether yours are in bud yet. Different plants in different planting environments will set buds and bloom at different times.