Form Runner Checkboxes not clickable

We have the following issue with forms running in Form Runner and built with form builder.

We have a series of checkbox options in our forms. We have noticed that the checkboxes cannot be checked or unchecked when you actually click in the checkbox. You have to click on the label to check the box.

Is there a bug fix for this or does anyone know a workaround?

Thanks

Found the problem:

the following css class did not properly define the clickable area for the checkbox image:

.ygtvspacer {
    height: 10px;
    width: 18px;
}

So the checkbox was only clickable if you clicked at the top of it.

Fixed it by extending height to 18px:

.ygtvspacer {
    height: 18px;
    width: 18px;
}