Hello,
Here is what I get today using Firefox (same problem after cache cleaning and page refresh) :

I use Firefox and haven't seen this particular issue on the site. Usually, if I come across this one some site, I will press CTRL-F5 to force a refresh.
The forum provides some stripped down mobile version automatically (since, well, your site itself is not yet responsive due to time issue working on that…). But glad it is not really bug since we cannot really do anything here since we are dependent on the forum vendor here…