Belated notifications?

[Michael Schwendt]

I'm facing an issue with F22 where notifications in GNOME Shell seem to
survive a shutdown/reboot. Eventually I notice there are notifications,
and when I look them up, they are about events from the previous day,
for example.

Something similar to "You may unplug the drive", and it has been
disconnected already long ago. Apparently, the system didn't notice or
didn't inform the notification system that it may expire the message.

"An important software update has failed", and clicking it only starts
gnome-software with no hint on what has failed or when. The last update
has been done with dnf, btw.