Certified GKH Gardening Expert
There are a few things that could be wrong here. My first guess would be overfertilization. Using something high in nitrogen, but not enough phosphorus and potassium can cause a lack of flowers. Over watering, could be the culprit as well.
This article will give you some insight to what can cause lack of blooms: https://www.gardeningknowhow.com/houseplants/peace-lily/peace-lily-blooming.htm