Got any plugins installed in your browser? What browser and OS?
Always worth double checking the PC with a second browser, Flash will generally be more constituent across browsers, but as browser manufacturers try to do more clever stuff it can sometimes get in the way of activity.
Might also be worth trying https://labs.thinkbroadband.com/speedtest
i.e. loading test over SSL which should remove 'software in the middle'
A much less intensive graphically version is http://labs.thinkbroadband.com/speedtest/?site=omega...
which might help if the browser is using a lot of CPU time
Edited by MrSaffron (Tue 05-Sep-17 11:57:55)