form not sending, loader spinning

I think it has something to do with the traduction plugin (WPML).

When I inspect the console while I submit a form I can see the 404 error on the POST query.

POST https://www.XXXX.com/XXXXXX/wp-json/?lang=escontact-form-7%2Fv1%2Fcontact-forms%2F3793%2Ffeedback&_locale=user 404 (Not Found)

The thing is there is a dash (/) missing because the traduction plugin adds “lang=es” in the URI.

Can someone help me figure out how to add that dash? I tried some code snippets but I didn’t fix it.