Windows 11 Pro 21H2 / Start 11 1.22
With a normal single high taskbar with the start menu on the left, there are no issues:

However, when the taskbar is expanded to two rows, the following seems to occur, though I don't know the precise trigger for it. It doesn't appear like this immediately, but after some delay:

This happens when the taskbar is locked or unlocked. To recreate it, you can try triggering an alert/notification with the Snipping Tool (SHIFT + WIN + S).