I tested lightdm-gtk-greeter instead of unity-greeter. In /etc/lightdm/lightdm.conf my system now has:
greeter-session=lightdm-gtk-greeter
With this change the slowness is now gone. Therefore this bug seems to be in unity-greeter.
I tested lightdm-gtk-greeter instead of unity-greeter. In /etc/lightdm/ lightdm. conf my system now has:
greeter- session= lightdm- gtk-greeter
With this change the slowness is now gone. Therefore this bug seems to be in unity-greeter.