I published an app created in Experience Builder that is using map widgets. The map widgets were connected to web maps with hosted feature layers. Today I learned about hosted feature layer views and had to switch out the hosted feature layers in each web map with the respective hosted feature layer views. I'm attempted to reconnect all of the widgets in the app to the new hosted feature layer views but the app is never able to find the new data source.
For example, the List Widget does not populate the data from the new layer, it just says "Waiting for data source" and in the Content tab of the List Widget pane the esri "processing" symbol just keeps running (see attached screenshot). I tried moving the List Widget to the pending list and back into the app but it still does not connect to the data. I've run into this issue multiple times and have not figured out a workaround other than deleting the widget and rebuilding it.
I could see why the widget is having problems finding the feature layer data source because it has been removed. I will get this logged and see if we can come up with providing better feedback to help the user in the event the widget cannot find the data source. The only way to fix this right now is to delete the widget and reconfigure as you mentioned above.