From the WP Dashboard >> Formidable PRO2PDF >> EXPORT >> Select the Formidable Form and Field Map Layout from the dropdown fields.
Check the “Attach file to Email notifications” is set to YES and the correct Email Action is checked.
Also, check to make sure there are no other Field Map Layouts for the same form, that are set to send Email Attachments.
Let us know the results as we remain at your service.