Since the file is put into a folder that is an indexed Group in DEVONthink, are you updating the index?
I use Hazel to help put stuff into DEVONthink. In Hazel I interrogate the content to figure out the right file name, tags, etc then Hazel moves the file to the DEVONthink Global Inbox and from there it is imported and Smart Rules can run.
In case of value: