I encountred the same issue. I had to change the script.js to make it work, I have added the following block to the $.wpcf7AjaxSuccess method:
var reCaptchaMessage = ‘<div id=”recaptcha-message” class=”wpcf7-response-output wpcf7-validation-errors”><span>Please check the reCaptcha </span> <div>’;
var recaptcha = $form.find(‘#g-recaptcha-response’);
if(recaptcha) {
if(recaptcha.val().length == 0){
$form.append(reCaptchaMessage);
$form.addClass(‘invalid’);
$form.find(‘img.ajax-loader’).css({ visibility: ‘hidden’ });
return;
}else{
$form.removeClass(‘invalid’);
$form.find(“#recaptcha-message”).remove();
}
}
It works fine.