I just had this happen to me the other day. See the photo..it was taken after 2 extra attempts to re-wash the glass.
I washed it outside in the sun and I guess I didn't get in inside the garage soon enough to dry it. Too busy learning how to use the new pressure washer and foam cannon lol.
Later that day, when I backed it out of the garage, I saw the disaster I had. Hard water spots on all the glass...I was freaking out. I recently got it back from getting Xpel PPF and ceramic on it too. I thought I was going to have to take it back to the shop for them to fix it for me. Last resort, we tried white vinegar on a rag and that got the spots off. Had to go over it a couple of times and then re-clean them with the glass cleaner.