I have installed the 21H1 update on several PCs with no issues, except for the PC that has Stardock Fences, CursorFX, and Multiplicity.
On that PC there are issues with these items being distorted or missing: Action Center missing, Notification area gets ghost images of taskbar items when the upward carot is pressed - these ghost images disappear when the mouse hovers over them but come back each time the upwards carot is accessed. Also, the Start menu disappears on occasion.
Upon rebooting, all items come back to normal for ten minutes or so, then the issues start again.
Stardock is my only app that alters the desktop so it is my prime suspect at this time. All the apps are the current version.
Anyone else have similar issues?
If I remove the 21H1 update on this PC, the PC returns to normal.
Next I will installing these Stardock apps on the other 21H1 PCs and see if this issue is reproducible on those PCs.