Clicking Labels changes Checkbox state

After some 508 Compliance work we recently performed on our site, I found that a majority of my previously working scripts had started to fail when attempting to click certain elements.

Most tests include clicking Checkboxes by clicking either the control OR the label (clicking both would essentially leave the control state unchanged)
Most test include clicking Radio Buttons by clicking the control AND the label (clicking both does not change state, which at the end is: selected)

What we see now is that clicking the label of a radio button changes the state of the first checkbox preceding the radio button.

I've attached a graphic showing what's happening.

If this occurred within the same control type (i.e., checkboxes or radio buttons), my first thought would be that the elements in my script were out of order.
The fact that clicking the label of a radio button changes the state of a checkbox indicates that something else is at play here.

When I brought this to my DEV’s attention, she said that this is occurring only in areas where the 508 Compliance work was completed, but when I brought this to our DEV’s attention, should didn’t see anything in the DOM that would account for this behavior.

I’m currently using version 2016.3.928.0, and have not updated my client in many months.

I looked through the Form and couldn't find anything reported similar to this.

Thanks for any help you might be able to provide,

Dan