Many applications (firefox, thunderbird, etc) slow to start on desktops other than Gnome
There is a bug with xdg-desktop-portal-gnome
(more details here ).
Workaround for gtk-based desktops (including Xfce)
sudo pacman -Rdd xdg-desktop-portal-gnome
sudo pacman -S xdg-desktop-portal-gtk
Workaround for KDE
sudo pacman -Rdd xdg-desktop-portal-gnome
sudo pacman -S xdg-desktop-portal-kde
Workaround for Lxqt
sudo pacman -Rdd xdg-desktop-portal-gnome
sudo pacman -S xdg-desktop-portal-lxqt
Workaround for desktops using hyprland
sudo pacman -Rdd xdg-desktop-portal-gnome
sudo pacman -S xdg-desktop-portal-hyprland
Workaround for desktops using wlroots
sudo pacman -Rdd xdg-desktop-portal-gnome
sudo pacman -S xdg-desktop-portal-wlr