If I might add a question: This thread has been referenced as a possible cause for an issue of mine with budgie that popped up very recently.
I just checked my installation history with the mentioned components:
[dromundkaas@Pure Videos]$ grep -i "budgie\|magpie\|mutter" /var/log/pacman.log
[2023-06-09T16:03:32+0200] [PACMAN] Running 'pacman -S --noconfirm --noprogressbar --needed --disable-download-timeout libwnck3 mesa-utils xf86-input-libinput xorg-xdpyinfo xorg-server xorg-xinit xorg-xinput xorg-xkill xorg-xrandr xf86-video-amdgpu xf86-video-ati b43-fwcutter broadcom-wl-dkms dhclient dnsmasq dnsutils ethtool iwd modemmanager networkmanager networkmanager-openconnect networkmanager-openvpn nss-mdns openssh usb_modeswitch wpa_supplicant xl2tpd firewalld python-pyqt5 python-capng downgrade pacman-contrib pkgfile rebuild-detector reflector yay accountsservice bash-completion bluez bluez-utils ffmpegthumbnailer gst-libav gst-plugin-pipewire gst-plugins-bad gst-plugins-ugly libdvdcss libgsf libopenraw mlocate poppler-glib xdg-user-dirs xdg-utils efitools haveged nfs-utils nilfs-utils ntp smartmontools unrar unzip xz adobe-source-han-sans-cn-fonts adobe-source-han-sans-jp-fonts adobe-source-han-sans-kr-fonts cantarell-fonts freetype2 noto-fonts ttf-bitstream-vera ttf-dejavu ttf-liberation ttf-opensans alsa-firmware alsa-plugins alsa-utils pavucontrol pipewire-pulse wireplumber pipewire-alsa pipewire-jack rtkit dmidecode dmraid hdparm hwdetect lsscsi mtools sg3_utils sof-firmware power-profiles-daemon upower endeavouros-theming eos-apps-info eos-log-tool eos-packagelist eos-quickstart eos-rankmirrors eos-update-notifier reflector-simple welcome duf findutils fsarchiver git glances hwinfo inxi meld nano-syntax-highlighting neofetch pv python-defusedxml python-packaging rsync tldr sed vi wget budgie-control-center budgie-desktop budgie-desktop-view budgie-extras budgie-screensaver eog evince file-roller gedit gnome-keyring gnome-screenshot gnome-terminal gvfs gvfs-afc gvfs-gphoto2 gvfs-mtp gvfs-nfs gvfs-smb lightdm lightdm-slick-greeter nemo nemo-fileroller nemo-preview network-manager-applet sushi totem xdg-user-dirs-gtk arc-gtk-theme-eos eos-settings-budgie eos-lightdm-slick-theme eos-qogir-icons'
[2023-06-09T16:05:40+0200] [ALPM] installed budgie-control-center (1.2.0-1)
[2023-06-09T16:05:40+0200] [ALPM] installed budgie-screensaver (5.1.0-2)
[2023-06-09T16:05:40+0200] [ALPM] installed mutter43 (43.5-1)
[2023-06-09T16:05:40+0200] [ALPM] installed budgie-desktop (10.7.2-5)
[2023-06-09T16:05:40+0200] [ALPM] installed budgie-desktop-view (1.2.1-2)
[2023-06-09T16:05:40+0200] [ALPM] installed budgie-extras (1.5.0-1)
[2023-06-09T16:05:41+0200] [ALPM] installed eos-settings-budgie (1.5-1)
[2023-08-02T09:31:27+0200] [ALPM] upgraded budgie-control-center (1.2.0-1 -> 1.3.0-1)
[2023-08-05T07:18:07+0200] [ALPM] removed mutter43 (43.5-1)
[2023-08-05T07:18:09+0200] [ALPM] installed mutter (44.3-1)
[2023-08-05T07:18:09+0200] [ALPM] installed magpie-wm (0.9.2-1)
[2023-08-05T07:18:09+0200] [ALPM] upgraded budgie-desktop (10.7.2-5 -> 10.7.2-6)
[2023-08-09T07:04:29+0200] [ALPM] upgraded budgie-extras (1.5.0-1 -> 1.6.0-1)
So mutter43 was installed, then later removed and replaced by mutter, while magpie-wm was installed as well. Now, that happened on the same day you documented the issue here, and as I usually update in the mornings (when the popup informs me of the number of updates), I didn’t have a chance to catch the problem.
Now, I have the linked strange issue. Could this be caused by a now broken or otherwise unintended installation configuration?