Contact Form doesn’t work with file attached

Hi!
My form sends the mail but does not attach the file. I already checked that the configuration of the form was correct. I contacted the server and they told me that it is not the problem on their part.
Please if you could help me I would appreciate it.

Here you can see the configuration: https://sudamericamuebles.com/contact-form/

The page I need help with: [log in to see the link]