I am also seeing the same thing as the screencast. It can be reproduced with tooltips and the Alt+Tab window.
Graphics card: Advanced Micro Devices, Inc. [AMD/ATI] Barts XT [Radeon HD 6870] Driver package: xserver-xorg-video-ati-hwe-18.04/bionic-updates,now 1:19.0.1-0ubuntu1~18.04.1 -- You received this bug notification because you are a member of Ubuntu-X, which is subscribed to xserver-xorg-video-ati in Ubuntu. https://bugs.launchpad.net/bugs/1860282 Title: corrupted desktop tooltips To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/xserver-xorg-video-ati/+bug/1860282/+subscriptions _______________________________________________ Mailing list: https://launchpad.net/~ubuntu-x-swat Post to : ubuntu-x-swat@lists.launchpad.net Unsubscribe : https://launchpad.net/~ubuntu-x-swat More help : https://help.launchpad.net/ListHelp