Some Layers in Feature Service not Editable through Map Viewer

[ChelseaP]

Putting this issue out there in case anyone else has come across it. Some of the layers within a feature service hosted on Enterprise are not editable in Map Viewer. When I try creating a new features I get the error in the picture below. For other layers in the same service I can still create features in Map Viewer. I can edit all the layers through Field Maps still. Seems to be an issue with editing only in Map Viewer. I recently made changes in the Field Maps forms for all the layers in feature service and changed the basemap. Not sure if any of those changes contributed to this issue as it was the first time someone tried editing the layer through Map Viewer - they had previously only edited through Field Maps.