I have a map service (named Map Service A) published in ArcGIS for Server 10.6.1. Its behind our firewall. We use SSO.
In ArcGIS Server Manager - Manage Services, the Sharing Properties for the service are checked for everyone (public) and enterprise GIS. All the Map Services have same sharing properties.
Under Content in Portal for ArcGIS, I bring this map service into a Map Viewer. I add two other map services as layers (from same source and named Map Service B and Map Service C). I configure the Map Viewer in Portal and save it. I share the webmap with Organization.
I then use the web appbuilder (in Portal) to create a new web map app.
When I open the web map app I can access all the layers from the Map Services.
However, when someone else opens the web map app a pop up message says that the layers in the Map Services cannot be accessed.
With all the Map Services having the same Sharing Properties, the webmap and webmap app having same sharing properties (organization), what could be the issue with others not being able to access the Map Services? I can access all the Map Services with no issues.