Some of my peonies have not sprouted this year!

I have a bed of old pass-along peonies. They have been planted for about five years and have been strong plants. Last spring the plants were covered in blooms, but the previous winter had several weeks of cold weather and snow. This winter was very mild. We had very few nights below freezing and a very early spring.

Did the mild winter and hot summer kill some of my plants?

Is anyone else having problems with their peonies?

I am in West Tennessee between Memphis and Nashville.