Problem is a little similar to https://forum.manjaro.org/t/windows-manager-broken/60160 but fixes there do not fix here.
In the middle of working with Thunderbird (which by the way causes a huge number of Activity Window refreshes), the WM switched to using focus-under-mouse and the windows will move only a couple of centimeters before I have to release the mouse and then drag the next centimeter. No changes of Settings has any effect (focus was still ticked for Click to focus),
The problem persists even after a cold reboot and for all (two) users, strongly suggesting the problem is not in user config. Also, on the lightdm greeter screen, mousing over the user name causes it to act as if the dropdown button had been clicked.
Please let me know what kind of logs would be helpful. This is journalctl after latest reboot and might be relevant but I don’t know what it means or why I haven’t had the problem ever before and why the problem started mid-session:
~ $ journalctl --boot=-1 --priority=3 --catalog --no-page
Jul 13 10:35:49 simon-intellga2066workstation kernel:
Jul 13 10:35:49 simon-intellga2066workstation kernel: ee1004 0-0056: Failed to select page 0 (-6)
Jul 13 10:36:12 simon-intellga2066workstation systemd[1]: Failed to start Terminate Plymouth Boot Screen.
░░ Subject: A start job for unit plymouth-quit.service has failed
░░ Defined-By: systemd
░░ Support: https://forum.manjaro.org/c/support
░░
░░ A start job for unit plymouth-quit.service has finished with a failure.
░░
░░ The job identifier is 132 and the job result is failed.
Jul 13 10:38:34 simon-intellga2066workstation dbus-broker-launch[1477]: Activation request for 'org.freedesktop.Avahi' failed.
Jul 13 10:38:34 simon-intellga2066workstation dbus-broker-launch[1477]: Activation request for 'org.freedesktop.nm_dispatcher' failed.
Jul 13 10:38:35 simon-intellga2066workstation kernel: watchdog: watchdog0: watchdog did not stop!
Things I already tried: system is completely up to date as of today; re-installed lightdm and xfwm4; cleared /etc/X11/xorg.conf.d; changed Settings to under-mouse and back again to Click to focus - full system reboot after all these attempts.
PS I also have a problem with CTRL-ALT-F2 then CTRL-ALT-F7 never restores the session but just sticks on a black screen with cursor, which I plan to write in a different topic, but I mention it here just in case it might be relevant. Seems like lightdm and/or xfwm4 are not happy bunnies
It is impossible to say…
One guess - based on the 10 lines journal - disable and remove plymouth.
Other than that 
It would be nice not having to drag and pull information from members … please supply - at a bare minimum the system info from inxi -Fxxzc0 preferably piped through curl and uploaded to a pastebin - in which case the link will do.
inxi -Fxxzc0 | curl -F'file=@-' https://0x0.st
Thanking you most kindly, apologies if I had to ask what would be useful. The journalctl is everything there is from that command, which was copy-pasted from the posting guide, the output is not truncated or edited.
inxi is now here, again very many thanks for your help with the pastebin, a new adventure for me: https://0x0.st/8DkK.txt
just in case, also .xsession-errors: https://0x0.st/8DkB.txt
Also discovered another problem, when I touch CTRL, my Firefox text window shrinks to 30% (I have no idea if this is relevant, but it’s new today, so may be, so I mention it)
Not understanding even what the problem is makes it very hard for me to judge what is relevant, sorry.
For “disable and remove Plymouth” do you mean sudo pacman -Rns plymouth plymouth-theme-manjaro plymouth-kcm
Just… 
sudo pacman -Rns plymouth
The other listed packages are dependent upon it and will be removed as well.
Xfce wayland support is experimentaI - they are years behind Gnome and Plasma - so I suggest you use xorg - chosen before login.
I think there is a hotkey conflict somewhere in the input chain which causes a conflict of a kind - but I don’t what or why.
I noted you are using ibus - and I am out of my league with this - I only use one layout and default input.
Removing plymouth may not be necessary - but it was the only thing I could suggest…
As for removing plymouth you need to edit and save the changes
/etc/default/grub - remove splash from kernel arguments/etc/mkinitcpio.conf - remove plymouth from hooks
Also rebuild init and grub.cfg
sudo mkinitcpio -P
sudo update-grub
Oddly enough that did not happen, Pamac would not run that because, it said, dependencies were broken. So I ran it with plymouth-theme-manjaro included and it told me off for not removing plymouth properly… but did remove it.
Unfortunately, removing plymouth has made no difference at all, even after a hard reboot.
Did you also follow the advice given by @ManjaroDevOps, i.e. update grub and rebuild the initramfs?
I didn’t, missed it at 30% screen… I have done all as indicated, unfortunately, it has made no difference still.
Re
I can assure you I am not using ibus on purpose. I’ve never touched anything like that, knowingly, I’m pretty much out of the box apart from some goofing around with hard disk mounting services. Likewise I never knowingly installed Plymouth nor intended to use Wayland. Do they come with the distro? If not then there is something very very weird going on.
It might have been installed as a dependency for something else.
pacman -Qi ibus | grep "Required By"
plymouth does — unfortunately, because it has already long been a source of headaches for many people.
Wayland comes installed by default in the Plasma and GNOME editions because those desktop environments have been optimized for use with Wayland, and upstream recommends using them with Wayland instead of X11.
The Xfce edition however will normally use X11 by default because it doesn’t really support Wayland yet. However, if you installed another window manager, then that may have pulled in Wayland.
Wishing to express deep gratitude to both @ManjaroDevOps and @Aragorn, I’m not sure how to close the thread properly.
I discovered the source of the problem, and I’m ashamed of myself. Hardware. Bluetooth keyboard nearly out of power obviously sending rogue keyboard commands and signals. Disconnected it in favour of an old cable keyboard, and everything works just fine. It just never occurred to me, I’m so very sorry for wasting all your time.
How do I mark “solved” and acknowledge the expert help I received when none of the posts have been the solution?
Considering that neither of us knew the real cause — the Bluetooth keyboard — and that you’re the one who discovered it, the solution goes to you. 