So, I started to notice this a couple of days ago. It happens on Chrome and Opera, both browsers are up to date.
Chrome: Version 70.0.3538.67 (Official Build) (64-bit)
Opera: Version: 56.0.3051.43
On both browsers I have a buffer of +60 seconds and this still happens, (tried on both with 720p60fps and 480p). I tried on incognito mode (no extensions) and still happens.
Hardware acceleration on and off, still stutter.
I also noticed that sometimes it takes a couple of seconds to start a video after I click play.
Even when the video stutter, the audio it's perfect.
It's like a stutter of 1 second every 20 seconds.
My specs are:
R7 1700 3.6Ghz
16 GB RAM
Malwarebytes and Windows Defender says that everything it's ok.