On different webpages i had the issue that when writing text an old, probably cashed, version of the text appears and my written text is hidden. It then raptly switches between the life and the cased version. I have not really found a way to reproduce it only that it happens after a tab has been left in the background for some time. Reloading does not help only opening the page in a new tab held bot only for a short amount of time. I definitively find out if add-ons affected it but it did not seam like it. I also had similar issues on websites where you can draw, with the images flashing. Any form of input seams to effect which version of the text is displayed.