https://wccftech.com/microsoft-confirms-windows-10-bug-taskbar-introduced-by-kb5001391/

The Windows maker has today confirmed the blurry taskbar issue that was reported by several users in the past few weeks. "After installing KB5001391 or later updates, the news and interests button in the Windows taskbar might have blurry text on certain display configurations," Microsoft writes.

However, users have reported experiencing blurry text across the taskbar and not just the news and interests button. The bug impacts the latest Windows 10 version 21H1, version 20H2, version 2004, and version 1909, running Build 19043.964 or later.