This thing on my pan
I was going to leave a comment about what I think this is, but here's an article that does a much better job lol
This article basically saved me leaving a longer comment 😅 this used to happen to all my steel cookware, but I've changed how I cook with them now and haven't had it happen since
Could be too muche rinse aid being dosed by your dishwasher. White spots - not enough rinse aid, rainbows - too much rinse aid.