Form submit not populating form library columns (but saving does)

I have an infopath form which does not update columns in a sharepoint form library on submit, but it does populate the columns when the form is saved.

Using sharepoint 2010, infopath 2010. Fields have been promoted and submit data connection has been created. I’m sure there is something simple I am missing as when I save a filled in form it populates the library columns from the form fields, but does not do it when the form is submitted.