I make heavy use of the KDE desktop grid feature, which causes the desktop to zoom back and display all of the virtual desktops that are defined. I presently have 20 virtual desktops so, hands down, this is the easiest way for me to navigate among them.
There is, and has been for a long time, a race condition involving the desktop grid. I have my system defined so that when I move the mouse to the upper left corner of the screen, I go into that grid mode (which used to be known as expo mode). If there is a notification showing on the display, such as when I mouse over a link and am given some information about the link, and I then move the mouse to the upper left corner, and I get there before the notification completely clears from the display, then the grid mode hangs and hangs my display.
The display will remain hung for anywhere from several seconds to tens of minutes but, if I leave the mouse pointer in the upper left corner, eventually I will get into grid mode and con continue working.
Sometimes, the hang is indefinite and I have to kill and restart plasma and kwin to get control of my desktop back.
Alternatively, of course, I can restart the display manager but this has the effect of ruining all of my current work. I run many VMs, and often have sshfs sessions set up in those VMs, with editors open in other vms or the host accessing files across VMs...anyway, it can be complicated and restarting the display manager can result in a lot of work to just get back to where I was.
So, restarting the DM is very much a last resort.
Now, when I kill/restart kwin and plasma, the next time I move the mouse to the top left corner, I get grid mode. But only that one time; all subsequent attempts to get grid mode fail completely. It looks like the assignment of grid mode to that corner of the display is gone. I can reassign it, and it works once.
Grid mode seems to be working; I can access it using ctrl-F8 (the default keyboard shortcut) but that is inconvenient since it takes me away from the mouse to do it.
As a workaround, I have defined both the top of the display and the lower left corner to also give me grid mode and, when the top left corner stops working after a hang, I can continue to work using these other means...until, eventually, they too get lost the same way the top left gets lost.
So, does anyone here know how I can reset the display without logging out, without restarting the display manager, and without doing anything else that would disrupt my workflow to get grid mode working reliably again when I move the mouse into the top left corner of the display?