I'd love a heart to heart talk with them on this one - it's highly unlikely that explanation ...This today from Crosby:
“Apparently the problem I am being told on this is the metal of the Shackle is Alloy & the metal of the anchor is carbon which is probably causing this issue.”
I just ordered 5 of the hot dipped 3/8” Titans that @Hello Below recommended. Hopefully that addresses it. Worst case if they still corrode, I can replace them yearly for $7 a pop.
dj