make sure you have the correct value in your email-download shortcode for the contact_form_id — it needs to match the CF7 form. see https://www.ads-software.com/plugins/email-before-download/screenshots/
if that’s not it, then make sure your CF7 form is using field names like “your-name”, not “name”. WordPress has problems when you use fields with reserved words like “name” (or, at least it used to).
If neither works, uninstall everything, reinstall CF7 and get it working first from a test page that you make. THEN, once you get it working, follow the EBD instructions like you did before.
Also, it’s worth pointing out that another person recently reported the same problem on this support forum. It could be that the latest versions of everything don’t work & cause the issue you’re seeing. You could try to step back a little bit on one or more of the plugins & see if that fixes it.