Hello!!
It's hard to pass comment without seeing the workflow in detail and discussing the set-up, however, let's assume there's an issue somewhere which we can't fix, a work around would be to use the email tool to email the file as an attachment to your user.
Whether that's acceptable or not to your client though is another question!
I'd probably consider reaching out to Alteryx support on this as I think it's going to need a screenshare to get to the bottom of!
One further thing I can say is that your script is no longer refencing the saved file location given in your assets _externals\....
Ben