choffman PRO said about 3 years ago on Sign in with Apple :
Hey, one more question. :) 
Any idea what might be causing this error? Everything seems to be working correctly, I can authenticate / login into the web app. But Ithis flash message appears. I can't figure out what's causing "Nonce mismatch".  Any thoughts?
Could not authenticate you from Apple because "Nonce mismatch".

From the logs:
Logs:
ERROR -- omniauth: (apple) Authentication failure! nonce_mismatch: OmniAuth::Strategies::OAuth2::CallbackError, nonce_mismatch | nonce mismatch