I have had a few correct answers and been unable to answer them as the tick box is essentially and unclickable link. Upvoting works. Is this a common bug or am I missing something?

It's not an internet timeout or lag as the page stops loading without errors and I have tried it from different access points on different browsers and on different OS (mac windows and ubuntu). In the source it says href javascript:void(0);. This is what I get on mouse hover over also.