When I click the "Beta Sign Up" button, it opens TWO modal overlays. I noticed this because it broke tab order when I was filling out the form. Happens in bot

When I click the "Beta Sign Up" button, it opens TWO modal overlays. I noticed this because it broke tab order when I was filling out the form. Happens in both Chrome and FF 41 on OSX. I was able to close one of the overlays and successfully submit the other one.