This happened to me also.
I tried everything. Different browsers, different computers. In the end I emailed them, they did something to reset my account and it suddenly worked fine. No further issues.
Very odd.
I too am having issues with this page. What I think should be the correct answer just repeatedly resets the page. Occasionally it even flashes ‘solved’ but won’t move on.
Tried 2 different devices, 2 different browsers. I have cleared cache etc. Something not right.