Issues with attachment

Hi,
For some reason, this form does not attach the mp3 that i try to send to myself. It strips the mp3 out but sends the message.
I generated the tag. Placed the first code to the left and the second code at the bottom of the form.
When i go to the front end. Everything looks nice and good but after sending with attachment, i dont see the attachment but i receive the email.
It is not from my host because i have been using fast secure contact form but yours look nicer and cleaner from the frontend so i want to switch to your plugin but i have been having this issue for a while now.

When i switch back to fast secure contact form, everything works fine, so i know it has nothing to do with my host.

Please help.
Thanks

https://www.ads-software.com/plugins/contact-form-7/