Notifications incorrectly positioned when there are several monitors on Wayland

With a laptop monitor on the left and an external monitor on the right, if I run notify-send from a terminal on the left monitor, the notification is correctly positioned at the top right of the left monitor.

But if I run it from a terminal on the right monitor, the notification seems positioned on the right monitor according to the dimensions of the left monitor (so somewhere in the top right quarter, but not top right).

xfce4-notifyd 0.9.4, i.e. current git-master.