gsettings set org.gnome.desktop.wm.preferences focus-new-windows 'strict'

или

 dconf-editor здесь: org/gnome/desktop/wm/preferences
 

Отключить переключатель в Gnome-tweaks
В dconf в ветке org.gnome.desktop.wm.keybindings switch-input-source установить значение ['<Alt>Shift_L']

Текущие значения

sudo -u Debian-gdm dbus-run-session gsettings list-recursively org.gnome.settings-daemon.plugins.power | grep -E "sleep-inactive"

sudo -u Debian-gdm dbus-run-session dconf write /org/gnome/settings-daemon/plugins/power/sleep-inactive-ac-type "'nothing'"
sudo -u myuser     dbus-run-session dconf write /org/gnome/settings-daemon/plugins/power/sleep-inactive-ac-type "'nothing'"