Bizarre behaviour with output section

Bizarre behaviour with output section
0

#1

So recently the output area of all exercise pages have been shifting up to the top of the browser. I am using a Mac and working on Safari. It used to work well but only recently started to this!
I have included a photo of it happening. Every time I refresh the page, its starts again (from the normal position and slowly starts to move up)

Works well on Windows.

Any ideas?