I don't think I've seen an anchor in that bad shape younger than from the 1800's . As a completely inexpert opinion, that can't have been just bad or compromised galvanization , but also grossly inferior steel for marine use. It seems to be shouting "Chinese" export in spite of the label when purchased at WM. Ah, ...no offense intended to anyone in China who exports a quality product but everyone knows why that reputation has become widespread.
Luckily, that is easily fixed with a fairly simple procedure best followed in deeper water.
Remove the shackle pin, listen for the satisfying splash similar to the sound of an ice cube landing in a refreshing beverage, and install the authentic Delta or switch to the more appropriately-named Bruce .