Hi we are using Portal for ArcGIS and Web Adaptor 10.4 which are configured with IWA and Windows Authentication. We have setup a webmap which contains a number of layers from ArcGIS Server map services. Both Portal and ArcGIS Server are configured with HTTPS only. The webmap is shared to a a particular portal group, which the user is a member of.
We have then built a web application using WAB Developer Edition, and hosted on a separate web server.
When using the Out of the Box Print or Measurement widget from the web app, it prompts for login to the portal (attached)
Has anyone come across a similar issue?