John, thanks for your help. The problem is something related to what you mention, although the call to acf_form_head() was there since without it it doesn’t even render the form, the problem was that I needed to put this code that apparently calls all the jquery dependencies of the forms rendered with acf_form()
acf.do_action('append', jQuery('.modal_editar'));
So I can tell the community if you’re going to use acf_form inside a loop or if you’re going to use it with ajax, make sure you use this code.
NOTE: Replace .modal_editar with the wrapper of your acf_form()