When accessing icloud.com through Firefox, and reading / editing icloud notes, my screen constantly flickers only on one half black and white which is the currently open note, this can be reproduced to every note. I've checked other browsers, Microsoft edge, and internet explorer, this doesn't happen there. Here are some screenshots, when typing, or scrolling the page constantly flickers black and white on the open note. Only the right hand side of the note is affected, the rest of the screen / page remains unaffected.