In ArcGIS Online I used the create feature layer -> build a layer of type point/line/polygon. Fairly simple process.
When adding additional fields (data -> fields) to all three I noticed that point and line/ have the checkbox to accept null values however the polygon does not. Once I noticed this I created just a polygon feature class and it did have the accept null checkbox as expected.
Is this the expected behavior of this process? Or is something else up. I have attached two screen caps showing the differences. I can easily work around it by creating a separate polygon FC but figured I'd ask.