Firefox plugin clearkey

Hi,
I have this problem on eurosport.fr website to watch a video.
I try to disable all ad-dons and I have the same result.
the link is :
https://www.eurosport.fr/cyclisme/gent-wevelgem-femmes/2025/gent-wevelgem-femmes-100e-victoire-pour-une-wiebes-tout-simplement-trop-forte-son-sprint-en-video_vid2348807/video.shtml

The media is a screen capture of the problem.
It seems the clearkey plugin turn off.
Maybe someone can help me ?
Thanks

Nobody has the problem ?

It doesn't quite relate to your topic, but I can't see anything under vivaldi either. Just this black box. Even without the red warning seal.

I use firefox and vivaldi, with vivaldi there is no problem. Te problem is with firefox

Have you enabled any extensions on viavaldi to get it working?

Yes, still not working with firefox