I have a web map that I created in Map Viewer this year that our field crew has been using for data collection. This past week when I opened Field Maps to show a new field crew member how we collect data, the Add Item button was no longer showing. I eventually I logged into ArcGIS Online and opened the web map in Map Viewer (not classic). I went to one of the previously editable layers, selected Show Properties and Enable Editing was off. What would make it toggle off in the web map by itself? I toggled on Enable Editing (it did turn on and I could even edit a point), saved the web map, closed it to looked at another layer in my table of contents. I went back to view the web map in Map Viewer and Enable Editing was toggled off. The setting is enabled as long as I am viewing the web map, but if I leave the web map Enable Edits doesn't stay enabled for the layer. I made a new web map and a new hosted feature layer with the same results. In Field Maps it says the map is editable and not read-only, but no Add Item button.