The Cohhilition

So I just noticed some screen tearing whilst scrolling up and down web pages, and have no idea what could be causing it.
I have a gtx 980, which is around a year old, so hopefully it's not dying.
I'm running the latest drivers and browser versions.
Does anyone have any idea what could be causing this?

Does it happen on all browsers?

I have the same problem but appears to be Firefox only. I also have an Nvidia GPU, so not sure if it's a driver issue or Firefox.

Forgot to update this. It was only an issue on Chrome, Firefox and Edge were fine.
I turned ON hardware acceleration in the settings and it fixed the issue. I had previously turned it off as it was causing issues with YouTube. I find it strange that although I turned hardware acceleration off a few weeks ago, the issue with the tearing only started happening yesterday.