Broke for me recently too. I had to add this to my .xinitrc:
systemctl --user start xfce4-notifyd.service
David Barri via arch-general Wed, 21 Jun 2017 05:18:52 -0700
Broke for me recently too. I had to add this to my .xinitrc:
systemctl --user start xfce4-notifyd.service