Brand new ASUS RX 5700 XT, drivers 19.7.2, system is a new Ryzen 3900X machine (Asus Strix X570 motherboard), 4K monitor (AOC) on displayport. latest Windows 10.
Simply hovering over the tiles in Radeon Settings's panel for a game shows artifacts.
The attached video demonstrates it in the panel for Skyrim. Wait a few seconds for the mouse to move and observe the glitches.
Everything is configured as default, no overclocking, the card and cpu are cool, no other activity.