Try in a standalone installation. If the same issue, try in a standalone installation of Opera Beta and Opera Developer from https://www.opera.com/download. Maybe it's something that's already fixed.
You could try turning hardware acceleration back on and setting opera://flags/#use-angle to opengl. Or, set it to one of the other options. You could also try playing with opera://flags/#d3d11-video-decoder.
What other web browsers have you tried? Try in Vivaldi just to see if it also does it since it's a Chromium-based browser that's closest to how Opera handles videos.
and amites a sound like interferences.
Does that sound come from the screen or out of your speakers? Does it happen with all qualities of videos?