yes, I know, as I already stated. In fact, I can use Vivaldi on all these systems and with the exception of this website, it shows secure connections and plays video.
I am unsure if it is video codecs related to HTML5 or some other bug, but it would be nice to know what exactly is causing the issue because all the other browsers I have used work fine (Chrome, FF and Brave). It seems to be Vivaldi related...