It's actually disappearing from Outlook anyway, the hardware acceleration checkbox. I wasn't able to try it on a troublesome laptop today as it had already updated to an Office build without that option. For what it's worth, I went on to do a full reinstall with Windows 10 (build 21H2) and the latest Office build as well as all the latest drivers from the laptop manufacturers website (in this case Lenovo). Within half an hour we'd recreated the Outlook distortion issue