FYI......
Electroless Nickel plating was invented/created I believe in the 1940's (late) to coat the inside of railroad tank cars (!!!!!) to allow them to carry caustic soda (sodium hydroxide) solutions. It has become infamous for being one of the more passive coatings available.
Unless you have a very vigorous alkali, accelerated by some chlorides, I have significant doubt that you are getting attack on "well applied" EN...
Rudy Sedlak