Supposed to be 4-5' tall, is it a tree peony? If so, they take several years to get to their mature height. If it's herbaceous it might be in a less than optimal location, I've had a few that stalled like that and, after replanting in a spot they preferred, they started growing and blooming. There are herbaceous that grow much slower than other as well, though. Also, it might not be done growing for the year, depending on it's bloom time and your zone it might still be growing for another month or so. Do you know the name of the peony in question?

Sorry supposed to be 3-4' tall. It is a sorbet peony. I have another that didn't sprout at all. I dug it up and transplanted it to see if I can save it today. I saw sprouts when I dug it up but it was growing either.

I moved one that was in too much shade and had to compete with maple tree 10 ft away.