The last several of weeks, perhaps even a couple of months, there has been a graphical artifact that appears & disappears on screen that is likely related to visual handling aspect with dom0 that changed - but I have not changed anything in that category. My qubes is at v.4.2.3 thru normal progression, running on a system with an AMD CPU & and AMD GPU & KDE X11 vs. Xfce or Wayland, there is no attempt on my part to play with GPU passthru, no special audio qube, in most terms that ought to relate it’s pretty vanilla qubes. The character of this artifact is that a random sized row of anywhere from some small number of pixels to a fairly large size row of pixels to sometimes two or more separate lines of pixels just turn to black but seem to be sensitive to cursor movement to a certain degree, although not entirely related. This phenomenon isn’t specific to the one set of pixels, can occur almost anywhere on my screen - randomly appearing & disappearing.
The artifact though could be easily linked to other dom0-powered graphics oddities that I’ve seen over the years, but I’m fairly certain that this didn’t used to happen. I’ve noted also that dom0 (long before this too) could sometimes get out of sync with the visible cursor & where the effect of interacting with a qube’s application interface might be (especially with regards to the nested menuing of say a browser or a file explorer). One portion of that problem is not occuring at the moment (tonight for whatever reason but it does occur all to often) is that in a file explorer (say: Files The GNOME Project) you have some nested menu issues that are badly painted & not fully interaction-able via either mouse or keyboard.
In the screen snatch, this is a post right-click on a folder that travels thru the first menu to the second level menu (Open on that first level) for the hoped for item: Open in New Tab.
To, there have been instances of a random redraw of the dialog for something out of the blue (see my sys-net connection info dialog out of the corner of my eye paint black then repaint it’s interior aside from the outer red pixels leaving it looking pretty much the same as before but this rare event was notable - the blackened innards were for a not unsubstantial period of time (by my account, at least a half a second).