Red marks on edges of armpits after laser hair removal? Clinic claim they have never seen anything like this before. (photo)

2/3 weeks after my 4th laser treatment these round marks appeared in the exact same spot on both my armpits. They are very round and quite red marks, there was some visible sensitivity (a little bit of peeling) but aside from what I can see, I don’t feel any pain or soreness. I went to the laser clinic and they claimed they have never seen anything like this after laser hair removal. Any thoughts on what this might be?