When a video is playing, on any website, like YouTube, Facebook, Bilibili, Weibo, etc., for every couple seconds the screen will freeze for around one second while the sound continues at normal speed. This just happened for a few days. I've tried removing all add-ons, closing extra tabs, restarting the computer, and even re-installing Firefox, but none seemed to work. The internet speed is always fine on my end.

I have a two-year-old ASUS U4300F, Windows 10, Intel i5 8th gen, with NVIDIA discrete graphic card, if that helps.