The login window for our secured web app built with WABDE looked like this (the screenshot below), before our enterprise 10.9.1 update and WABDE v2.23 update.

After the enterprise 10.9.1 update AND the Web AppBuilder DE v2.23 update (to match 10.9.1), our secured web app sign-in window looks like this -

This Web App needs to be secured so it contains a web map that is shared only with members of the organization.
How do I get the login window back to the way it was?