Radio Buttons not working

This is a continuation of https://wordpress.org/support/topic/checkboxes-and-radio-buttons-not-working?replies=7.

I switched to twenty-fifteen as per your last suggestion and the problem still occurs. Since my form was rather lengthy, I created a simple form

[radio radio-324 "one" "two" "three"]
<p>[submit "Send"]</p>

But still the problem persisted… It would allow submit without ANYTHING being selected.

I only have ONE plugin “Contact Form 7 ” v 4.2.1
WP 4.2.2 on twenty-fifteen theme.

I started investigating the validation process, and here is what I found.
I think the problem is in checkbox.php in function wpcf7_checkbox_validation_filter.

if ( $tag->is_required() && empty( $value ) ) {
		$result->invalidate( $tag, wpcf7_get_message( 'invalid_required' ) );
	}

return $result;

For a radio button, there is not a is_required object, and since you are using an “AND” the empty value does not apply. So it just does not do any validation against the [type]=>radio

https://wordpress.org/plugins/contact-form-7/