Not sure but I think what you’re saying is that it crystallized, is that right? The pan shouldn’t have anything to do with that, but you may want to check with the manufacturer as to what the upper limit of safe temps is for your particular brand of non-stick. Caramel starts around 340F and can go as high as 380F for dark versions.
For caramel, it doesn’t really matter if it crystallizes, it will still liquefy again when it reaches caramel temps. To avoid crystallizing, when the mixture first comes to a boil, you have to stir slowly until all the little crystals are dissolved, and then cover it for a while so that the condensing steam washes down the sides of the pan and helps dissolve any crystals lurking there. Basically, any place you have crystals (spoon, thermometer, sides of pan) can trigger crystallization of the whole mass.