Publishing a survey in Survey123 Connect for ArcGIS to Portal for ArcGIS configured to use Integrated Windows Authentication (IWA) fails to publish as it freezes on the 'Creating Form Item' step.
Use a built-in Portal for ArcGIS user AND set up IWA on the web adaptor only (allow anonymous access on the Default Web Site and server machine in IIS), then bypass the web adaptor by configuring Survey123 Connect for ArcGIS to go directly through the port. For more details, see <a href="https://geonet.esri.com/thread/190727-creating-form-item-during-publishing-to-portal-from-survey123-connect-hangs#comment-694343" target="_blank">https://geonet.esri.com/thread/190727-creating-form-item-during-publishing-to-portal-from-survey123-connect-hangs#comment-694343</a>.