Hi Dimas,
This issue I reported like a year ago, and I you solve it, but as I have a new clean site this fix is missing, I can not locate the ticket when you replay with the solution this time, maybe was in another ticket with more that one request, so this new site I have create is clean joomla, but I use the same database, of the old site.
Do you have options to access ssh? I need to trace the code, seems I found something wrong on your site, i see your site call file window.css, which that file is not not be needed.