I don’t know if I have a piriformis issue or if it is a back issue but my left glute sometimes hurts. I’ve had this before.
I think I brought this on by trying to go deeper in my goblet squats (to the stool, rather than to the chair) and I might rest from these for a few days.
Today, I jogged 5k (yes, right around 40 minutes; I was that slow) and walked 5k (50 minutes) and I did have some pain at the lower part of Bradley Park.
These, plus hip hikes should help.