We have an ArcGIS Online Organization account that has content from another Organization shared to us. This includes a number of feature services and webmaps. When this was initially set up, we were able to access all of the shared content through ArcGIS Pro for a few weeks, then the access 'broke'. ArcGIS Pro maps that had the online content saved would now show broken links ('!').
We are able to view the shared content in the Catalog window, but are unable to add it to maps. Attempting to add a feature service layer results in a "Failed to add data: <service URL>" message. Attempting to add a webmap results in an empty map. Connecting to the feature services' rest interface shows "Token Required" (this may be normal, but adding for extra info). I've tried re-logging into the AGOL account, restarting Pro, testing on other machines, but no joy.
We asked the other Organization to look into this to see if they could address it but they are unable to to determine what might be causing this. Anyone got any ideas?