Hi folks I fitted some EB Cobalt flats in March. I really like them and have played them a fair bit at home. However I noticed yesterday that they have rusted quite badly (and quickly) around the 20th fret and the playing area over the pickups. Is that normal for these strings? I hope not as I really like them - I’ve contacted Ernie Ball so will let you know what they say. Maybe I got a dud set?  Anyway I've ordered some Labella super light flats to try as for some reason I’ve never gi