The latest Windows 10 2004, 20H2, and 21H1 preview update is causing display issues and glitches on the taskbar’s system tray. Windows 10 users affected by this bug found that it could be fixed by uninstalling the KB5003214 preview update. Unless Microsoft fixes the issue before June 8th’s Patch Tuesday, all users will be faced with this issue. The bug is caused by disabling the News and Interests widget on taskbar. Once you enable the widget again, the icons begin to display correctly.
Source: https://www.bleepingcomputer.com/news/microsoft/windows-10-kb5003214-update-causes-taskbar-display-glitches/