Introduction
Occasionally, when trying to authenticate with DUO mobile on MacOS or iOS, the operating systems' default content restrictions will block the DUO service. This results in either a page reading "This site cannot be reached" or a white screen with no other text, rendering users unable to authenticate with DUO. This article explains what to do in case this issue occurs.
Resolution
DUO has made an article detailing the solution to this issue in their own knowledge base, which can be found here. NOTE: Ignore the portion of the article where it instructs you to enable JavaScript. This part of the solution no longer works.
After performing the steps in this article, it is advised to restart your device to ensure that the software/website recognizes the change.