Hello Mike,
My name is Joe and I work in Esri Tech Support. This behavior sounds like a bug that we have logged for version 10.7.1, which is marked as fixed in version 10.8. The defining factor for determining whether or not you're encountering this bug, or if it's something different, depends on your Portal for ArcGIS authentication. Do you utilize IWA for authentication?
The bug name is BUG-000125033: Users signed in through Integrated Windows Authentication (IWA) cannot search for layers under My Organization in Map Viewer.
If you are encountering this bug, I would recommend contacting Esri Tech Support to be attached to this bug so you can track its status via MyEsri. The listed workarounds are as follows:
- Add layers to Map Viewer by clicking Add > Add Layer from Web and pasting the item's REST URL.
- Creating a custom role using the User role template and adding only the Collaboration check box appears to resolve the hanging issue. Uncheck the other administration privileges that are automatically populated when collaboration is selected. This minimizes any privileges needed to work around this issue.
Feel free to respond with any additional questions or concerns!
Joe