Thanks for your reply, Ryan. So far it seems limited to Zillow's web site and app. I worked with Apple Support this morning with the following results: There's no error; it's just nothing happens. After pressing/clicking on “Sign-in with Apple,” it requests I verify my ID using Touch ID, then just returns me to the same sign-in screen that offers “Sign in with Apple.” It never advances further, or offers to share or hide my e-mail. I deleted my old Zillow account, tried signing in to Zillow using Safari, clearing cookies in Safari, and on my iPad uninstalling and reinstalling the Zillow app, deleting my old Zillow passwords. Nothing. I logged in to appleid.apple.com, visited the 'security section' and found Zillow listed there. At Apple Support's direction, I tried deleting and reinstalling the Zillow app again and tried logging in. Nothing. I then went back to appleid.apple.com etc. and clicked on 'stop using Apple ID.' THIS TIME it (for the first time) requested whether I wished to share my e-mail (I answered 'no'; after all, that's the whole point) then attempted to sign-in, and still it did not work. Tried also via Safari with no better result. So Apple Support directed me to Zillow's app developer/publisher, for which I presently have no more time to dedicate. I can still do that, but it seems an unrealistic expectation of this particular (unpaid) end user and I simply want the darn "Sign-in with Apple" to work.