Save Button requires double-click in IE to trigger NWF2013 Workflow. Why?

We have a SharePoint 2013 list and accompanying InfoPath form.  On the InfoPath form we have separate save and submit buttons.  We want the save button to save the form update in progress to the sharepoint list and we want the submit button to change a status field which triggers the Nintex workflow.  When accessing the form via the IE browser, we have to click the buttons twice in order for them to take affect.  We can't figure out why it is behaving this way.  Thanks for your help.