NotifyOSD has a fallback to alertbox function and maybe this is being called in stead of a normal notification.
More info here: https://wiki.ubuntu.com/NotifyOSD#Fallback_alert_boxes
The first lines read: "For cases where applications have expected the notification system to allow interactivity without checking whether it actually does, and cases where applications have expected the notification system to display a notification indefinitely, Notify OSD should show an alert box as a fallback."
NotifyOSD has a fallback to alertbox function and maybe this is being called in stead of a normal notification.
More info here: https:/ /wiki.ubuntu. com/NotifyOSD# Fallback_ alert_boxes
The first lines read: "For cases where applications have expected the notification system to allow interactivity without checking whether it actually does, and cases where applications have expected the notification system to display a notification indefinitely, Notify OSD should show an alert box as a fallback."