I'm working on a WAB app that is using a web map that I have shared with everyone. The web map contains a feature layer that I have only shared with a particular group, which I have made myself a member of. When I launch the application locally (via WAB), the web map is automatically added and includes the feature layer (I assume it's using ADFS?). If I take myself out of the group and launch the application locally, I get a dialog that says the layer cannot be added to the map (I'd like this dialog to just not appear at all but that's further down the road). I am not prompted to sign in to ArcGIS Online to access the item, I just click "ok" and the map ends up loading without that layer.
When I deploy the application to a web server and run it, I am prompted to sign in to access the item on ArcGIS Online whether I am in the group or not. I've tried every variation of username/password I can think of and I can not figure out what username and password it is looking for. It seems that it should be the same credentials that are used when I use ADFS to log in to ArcGIS Online? Anyway, I basically can only "cancel" and then all the layers except for the group shared layer load up.
Am I missing a step somewhere? I have set up a proxy and believe I have it working. Not sure if I might need to register the app in AGOL? Not sure what the serverURL might have to look like, in proxy.config, if I need to use a proxy. I'd appreciate any thoughts or links that I might refer to that might help me move along or better understand this.