Screensaver popup

Hi,
I have issue whenever watching video, if i don’t touch / move the mouse and let the video screen remain playing the show, after few minutes, it will auto show up a screen saver and when i revert back to the show, the screen will not play and only the voice of movie remains playing.

I have turn off the screensaver in setting, but still can’t help.

Appreciate expert advises.

Thank you.