Thank you all for your continued patience and perseverance with this issue.
I understand that Wayland and X11 are two different systems and I compared the two only because the screen flicker bug on intel HD grapics cards has identical symptoms on Wayland to unpatched X11. I figured that there might be a clue as to what generally needs to be done on Wayland to fix the bug.
Pretty sure this is not a type of mouse issue as I can recreate the exact same results using a trackpad, bluetooth and hard wired mouse. The glitch seems to happen only when the cursor is at specific x-y co-ordinates and seems to occur due to the graphics card failing to correctly redraw the cursor and the background along a single line of pixels.
I still think that it is very relevant when patching X11 that the contents of the 20-intel_flicker_fix.conf file does not seem to need any tweaks, only a pointer to what graphics card is being used.
Please keep up the good work, you are all the best whatever the outcome.

    BuzzPCSOS No problemo I have been killing time lately but got get back to real life for awhile
    (Oh what fun..lol) I just try help out my fellow Solushians I dont pretend to know everything but usually more
    Tin caps the better.

      12 days later

      I have some possible news regarding this issue. On my Plasma laptop, I've been using X11 since the work-around was provided to prevent the screen flickering we've seen with Wayland. Just now, I decided to let DoFlicky check to see whether there's something new for my video adapters in this Latitude (Intel + NVidia).

      Turns out, there was something. I selected the recommended driver, and another dependency was required. Somehow, I ended up with 3 items to install, and along the way I briefly saw something about a Wayland improvement.

      After shutting down and restarting, I dragged my mouse pointer all over the lower part of the screen, for quite a while, and there was nary a flicker. There was one drawback, but it's one I can live with. Although Plank is installed, it won't launch. I even reinstalled it, but no joy. However, I can live with that because the Latte dock does install and it works just fine.

      Again, a disclaimer: I started on this adventure about 15 minutes ago, and much of that time has been devoted to writing this message. I hope this will work for us all, and keep working for us. You now know as much as I do about it. Happy, happy, joy, joy! Now to update all the other Plasma machines here. 😃

        Woah ... this is even better! For a long time I've needed to use X11 in order to take VMs to full-screen (HOST+F). Recently I learned of a work-around involving turning off the mini-toolbar in the VirtualBox settings (the one at the bottom of the list). That's not a critical feature, so it was better than nothing.

        After seeing that there's almost no screen flicker anymore with Wayland on this laptop, I decided to try adding that mini-toolbar setting back to a VM (a Plasma VM for testing Discover), and seeing if it would still lock everything up if I switched to full-screen on Wayland. Turns out, that's fixed, too. Here's that VM on a wayland session on this laptop. And absolutely zero locking up, as you can tell from the items I've launched, including Spectacle, which I used to snap this screenshot.

        Now I've got some work-arounds to remove from a bunch of VMs. Just don't need 'em anymore. And to be perfectly honest, I have seen a couple of brief flickers since I wrote the first post about this. But they were trivial, lasted for less than a second, and I have no idea whether they're related to the earlier phenomenon. Again, they're nothing that will keep me from using Wayland full-time on all the machines here.

        WetGeek However, I can live with that because the Latte dock does install and it works just fine.

        Irony because I installed Latte in XFCE and it would not launch today.🙂.

        What's the difference in Plasma between X11 and Wayland so far? Minor screen flickers so far? I have not looked up all your wayland/plasma reports or @BuzzPCSOS 's either. (suddenly got reeeeeal curious today what the future brings). Thanks

            I have been dealing with firefox screen tares and black screen freeze only while watching video mostly (the desktop and all no issues) and finally have it running with hardware support with no issues so far (time will tell)
            Alot Alot of reading about video.
            All I can say so far it doesnt use the 20-intel.conf file.
            2days of work..

            Glad your issues got solved or at least better.

            But wait ... there's more! The next step was to updte the drivers on my two Optiplex desktops upstairs (workstation and torrent server), and when I lanched DoFlicky, it told me that nothing was needed for these machines. These have no Nvidia firmware, and the Intel part is different from what's in the Latitude laptops.

            One thing is the same, though. Plank isn't working on these machines since this week's update. Apparently the death of Plank may have had nothing to do with the new video drivers. As on the laptops, Latte is working just fine, though, so I just need to make a change in the autostart settings.

            Bottom line: there may be updated drivers for your computers with combination Intel/Nvidia cards, and it doesn't cost anything to launch DoFlicky and take a look. (That's Hardware Drivers in the Setting section of the menu.)

            brent I installed Latte in XFCE and it would not launch today.

            That's what happened to me when I tried that a while ago. Apparently it's Plank for the GNOME machines, and Latte for the KDE machines. For a while, I was using Plank everywhere, but as I've just written, that ended today.

            We indeed live in interesting times.

                WetGeek We indeed live in interesting times.

                And one more thing that started working now, that hadn't been working recently. That's the night-light feature. My eyes are sensitive to bright light ever since I had cataract surgery. And when I worked at a computer when it's dark outside, and I opened up a Vivaldi session, it was painful. But night-light is obviously working now, and it's much better on the eyes.

                  I'm updating the Latitude laptop with Xfce on it now. This is what DoFlicky looks like when it has that upgrade for Nvidia:

                  Since I have no interest in playing legacy Windows games, I passed on the 32-bit option, but others may want that as well.

                  This is the dependency I mentioned earlier. After this, the upgrade will be installed. This is where I saw Wayland mentioned. I'm a little confused about whether the flickering was actually an Intel or NVidia issue, but I can't argue with the results.

                  Authentication is needed, but a convenient dialog lets you do that from here. When the upgrade is finished, a restart is needed.

                  WetGeek That's what happened to me when I tried that a while ago. Apparently it's Plank for the GNOME machines, and Latte for the KDE machines. For a while, I was using Plank everywhere, but as I've just written, that ended today.

                  We indeed live in interesting times.

                  it's funny for Latte, I did the menu launch, nothing. I do the terminal launch it says Latte already running but nothing for eyeballs to see...I had to file an XFCE Plank bug at dev tracker today---again the parallel irony with Latte---it wouldn't show dots for the minimized apps....until I lowered refresh rate which I thought was weird.

                  WetGeek Apparently it's Plank for the GNOME machines, and Latte for the KDE machines

                  that needs to be made clear somewhere🙂. I dragged 50 k-packages into XFCE for nothing.

                  like you I never have a negative reaction. it's funny quite often, needs to be noted, and very much a great adventure. too bad about the Lions and I don't like the Chiefs and my teams not in it anyway so I digress 😎

                        I just finished upgrading the Xfce laptop and restarting, and as one might expect, there were some differences. Unlike on the Plasma laptop, there was no problem running Plank either before or after the upgrade. So I'm less convinced that the upgrade had anything to do with Plank. I think it was this weekend's update that did that instead. While it was up and running, it stayed that way, but once it was shut down, it wouldn't start again.

                        brent I dragged 50 k-packages into XFCE for nothing.

                        I haven't tried that, but I wouldn't expect it to be a problem. I've used other KDE applications in every GNOME-based computer and VM I've ever created, without any problems. I figured the Plank/Latte issue was a one-off.

                            WetGeek . I figured the Plank/Latte issue was a one-off.

                            thanks for confirming this. I figured an anomaly but needed a 2nd opinion

                              My Latitude HD graphics card still flickers here :-(
                              I checked for an updated graphics driver but DoFlicky said there were none there which figures because I only have Intel HD Graphics 620 and no extra NVIDIA card.
                              I searched for the egl-wayland dependency in the Software Centre that @WetGeek mentioned, it is not installed on my laptop and I'm not going to try installing it on a hunch that it might make things better.
                              I will continue to run in wayland as the flicker is not that bad and it only takes a small mouse movement to stop it. I can see that there are Exciting Times ahead for all of us on Solus and maybe a future update will end the flicker for good.

                                BuzzPCSOS maybe a future update will end the flicker for good.

                                I'm hoping so as well. Now that the cause and the cure are known, it's time to get it fixed for everyone who's affected.

                                And now that I'm working with it more, I'm seeing that it's not entirely cured on my latitude, either. But now it's almost unnoticeable, as you wrote, and stops the flickering itself when I just keep using the mouse. It used to be a violent shaking of the image that made me think something was about to break, I'd need to move the mouse pretty far away to stop it.

                                Plus, the other changes I mentioned are very welcome. Night color working again, for instance. It's not yet dawn here, and my eyes appreciate that it automatically changed. And the night color icon now stays visible in the system tray and can be toggled on and off. Before, not only did that icon not do anything, but it jumped back into the hidden icons secetion if I clicked on it.

                                    WetGeek Just need to share this. I took a serious look at my display tonight. Compositor settings, Resolution, Refresh rate, RGB Range, Legacy Applications preferences, everything! I also spent a while watching a video by Chris Titus called Fix Screen Tearing in Linux. To be honest I did not follow any of his advice except to run xrandr to show the capabilities of my video card. Turns out that my refresh rate tops out at about 58.8Hz. I also noticed that in System Settings - Display Configuration is set to 60hz. On a whim I lowered it to 40Hz and applied the change.
                                    So far so good!
                                    I can't make my screen flicker anymore in Wayland. I have spent several minutes trying to find the sweet spot where the screen flickers and it seems to have gone :-))
                                    Is it just me? Please let me know. Could it really be that simple?

                                        BuzzPCSOS Is it just me? Please let me know. Could it really be that simple?

                                        I'll give that a try and see if it gets rid of what little flickering I still see. Thanks for the idea!