Checkbox missing in translated language

Hi,

I’m trying to translate from English to Italian a custo login box with a checkbox.
The English version of the checkbox is:

<label><input type="checkbox" name="xoo_el_reg_terms" class="xoo-aff-required xoo-aff-checkbox_single" value="yes">I accept the <a >Terms of Service</a> and <a >Privacy Policy</a></label>

And the translated version I try to save is:

<label><input type="checkbox" name="xoo_el_reg_terms" class="xoo-aff-required xoo-aff-checkbox_single" value="yes">Accetto i <a >Termini del servizio</a> e la <a >Privacy Policy</a></label>

but when I save, in the translation box I get:

<label>Accetto i <a >Termini del servizio</a> e la <a >Privacy Policy</a></label>

So all the “input” tag part is gone and the checkbox does not appear on the translated page. Why is this happening?
Thank you!