Lighthouse check boxes are a bit different than regular check boxes, which may be the cause of your problem switching from v6 to Lighthouse. The function SSI_CustomGraphicalCheckbox can be very helpful for situations where you want to actively watch for changes to a Lighthouse check box.
Here's the code I put in my Q11 to accomplish your goal:
<script type="text/javascript">
$(document).ready(function(){
$('#Q11a_div').hide();
$('#Q11b_div').hide();
$('#Q11c_div').hide();
$('#Q11d_div').hide();
$('#Q11e_div').hide();
})
function SSI_CustomGraphicalCheckbox(graphicalCheckboxObj, inputObj, boolCheck) {
var id = '';
var disp = boolCheck ? 'block' : 'none';
switch (inputObj.name) {
case 'Q11_1':
id = 'Q11a_div';
break;
case 'Q11_2':
id = 'Q11b_div';
break;
case 'Q11_3':
id = 'Q11c_div';
break;
case 'Q11_4':
id = 'Q11d_div';
break;
case 'Q11_5':
id = 'Q11e_div';
break;
}
document.getElementById(id).style.display = disp;
}
</script>