Mine is not truncated, however it doesn't change its size. I use small taskbar at the top of the screen, and it always stays at "Medium" size regardless of the settings. Small and Large all look the same.
Now I see what the issue is "Enhance the taskbar" is now mandatory for this Windows 11 update to change the taskbar size I guess. I've always had it disabled because then "TrafficMonitor" is not visible in the taskbar.
I enabled "enhance the taskbar" just for testing and I see the exact same problem as you guys. Vertically truncated taskbar.
Windows 11 (microsoft) just keeps on giving. I hate Micro$oft.