Whilst attempting to block a browser-window-starting/new-tab-opening iPhoneX ad-thing, I thought I should 'refresh' Firefox, which basically starts off from scratch but just keeps the bookmarks.
Since doing that, some websites have a green ghost on the text and horizontal lines when scrolling, none worse so than the PBBans home page! It was NOT like that before the refresh, and I vaguely remember I fixed it once before, but I can't find how!
Has anyone else had this and fixed it? I've turned off the hardware acceleration on Firefox already.
While trying to catch a printscreen of the effect I noticed I get the same effect if I move the screenshot around. So I'm guessing it's not the browser's fault but somehow, suddenly, a monitor or graphics issues. I have no idea why, as other than a load of malware/adware tests (all negative) I have only refreshed the browser.
Help still required if anyone knows how to fix it.