William, try to use this comand, it works for me:
gsettings set org.gnome.desktop.wm.keybindings switch-input-source "['<Alt>Shift_L']"
William, try to use this comand, it works for me:
gsettings set org.gnome. desktop. wm.keybindings switch-input-source "['<Alt>Shift_L']"