<select class="form-control text-uppercase rounded-0" name="x_brand" required="required" t-att-value="request.params.get('x_brand', '')">
<option value=""></option>
<option value="A">A</option>
<option value="B">B</option>
<option value="C"></option>
</select>
I have the above code on website contact form, but even if the <select> tag is required, it is possible to submit the form with the field empy (on all the other fields, also other <select>, the required is working as expected). The submit metod is the following:
<div class="form-group">
<div class="col-md-offset-3 col-sm-offset-4 col-sm-8 col-md-7">
<span class="btn btn-md o_website_form_send" style="background-color: #127749; color:#fff;">Invia</span>
<span id="o_website_form_result"/>
</div>
</div>