Your last sentence is likely right, by default the form issues a network request. I've been using a dialog form to update an iframe (it's an editor) so it does

Your last sentence is likely right, by default the form issues a network request. I've been using a dialog form to update an iframe (it's an editor) so it does work as normal the target iframe gets reloaded. It does not close the dialog though. I can't produce the case where hitting enter closes the dialog. It should be the same as `<button type='submit'>submit</button>` which also does not close the dialog. FWIW I learned yesterday that a button _can_ close the dialog: <button formmethod="dialog">Update & Close</button>