I don’t notice it at other locations. It’s not objectionable to me, but it does taste like what I said. This is a KFC/Taco Bell store.
In all cases, I prefer they create safe uses alternative for the leftovers instead of just throwing away food. Of course McDonald’s doesn’t actually have much edible food.
I ate my first Filet-O-Fish sandwich in Seattle in 1962, on a trip to visit the World's Fair. It became my go-to sandwich. Over a half-century later it still is my McDonald's go-to. Always say light tartar sauce.