The store page is wonky, so when you go to the checkout you'll see the discount applied as it should. It is mildly annoying, but at least you'll get it for half off.
Works fine for me, on store page and checkout.
Hence why I said wonky, it didn't show on the store page for me while showing on the main page and checkout. It may vary from person to person but I am glad that it didn't affect everybody, or it may have been dealt with in some form in the backend.