Hardcoded checkbox not work

I created a CF7 form using an hardcoded checkbox (html instead of shortcode) for GDPR but it send email also if checkbox isn’t flagged. I’m trying from hours without success, could anyone help me?

For hardcode the checkbox, I used classes that the shortcode generates in html – integrating them with a better graphic solution using css. I also set “acceptance_as_validation: on”.

This is my code used in CF7:

<span class=”wpcf7-form-control-wrap acceptance-53″><span class=”wpcf7-form-control wpcf7-acceptance”><span class=”wpcf7-list-item”><label class=”cont4iner”>GDPR Privacy text.
<input type=”checkbox” name=”acceptance-5″ value=”2″ aria-invalid=”false”>
<span class=”checkmark”></span>
</label></span></span></span>

When using it, you can click Submit with success without flag the checkbox. Anyone know why and how to solve it? Thank you very much!