I have a web app that our city uses to track street light outages, and it only has a publicly shared feature service layer with one editable field (if the light is working or not). When I am signed in to my account, I can edit at will. If I sign out or a public user tries to edit the layer, no field is editable, therefore rendering the app useless. Was there another WAB update that messed this up and I have to wait for a fix, or is this something as simple as recreating the feature service layer?
Looks like the capabilities on the service may have been changed (possible overwritten or otherwise updated recently?) - the StreetLights feature service used to collect outages only allows updates. Try enabling "Add Features only" option on the item details page for the service. The public should then be able to report outages as before.