I am having strange issue while uploading file from Custom SP List with DFFS configured along with Related attachments configuration (vLookup). Since I tried re-installing DFFS for editform at that time it got worked for first it displays fields to update one file got upload.
Again I got the same issue while uploading attachment which will eventually get stored in seperate document library with lookup mapped with Custom List. I re-visited the configuration settings. I am not sure why it is behaving like that. It is working for other sites.