On my Win10 PC with two monitors, with DF 8 Beta 4, the secondary taskbar displays as black for 3 seconds after I unlock the PC, then it fills in with buttons.

I recently had a problem with my screen saver interacting with Win10 and another GINA application (single sign on add-on) on Win7 and had to make some window class bit changes for the screen saver window to be detected properly and e.g. not show up underneath the add-on taskbar from the SSO software.

Perhaps changing some extended Window class bits would fix the DF taskbar.

Perhaps you could look at how long this takes? I am not sure if it is the re-load of the bar, or the detecting the unlock, but it is taking at least 2.5 seconds on my (fast) PC.

Perhaps the bar could just be hidden and unhidden? That way it could be kept up to date as well?

It seems better (though still slow ) when unlocking, but it seems like it is very slow to hide when locking now?

It seems it is around one second or 1.5 seconds

It seems like I did not see it when pressing Windows+L before this latest beta - it would be covered by the black lock screen immediately.

I think if I just rollback to an earlier beta of 8 it didn't exhibit the problem.