Anyone out there experts with the Smart Editor and Edit widgets? I have a strange situation where all the settings should allow me to edit existing or add new features to a hosted feature layer (I have checked many, many times) and I can in a web map fine. But when I try with the Smart Editor or Edit widgets in a web app I can edit existing records fine but nothing I do will allow me to add new features. No error messages. Either I digitise the feature and nothing happens (Smart Editor) or the Save button is greyed out (Edit). I suspect this message has something to do with it...

...so I have all my fields displayed on at service, webmap and widget level but some required fields like OBJECTID and GlobalID just will not display in the widget settings. Anyone have any ideas what might be going on?
Other thing to note is the feature layer already has 25,000 features. Could this cause issues with the widgets but not editing in a webmap?