cannot find/read/delete new notifications on lock screen
In Ubuntu 17.10 the lock screen tells me that there is a new notification from Backups and another from the Software Manager. However I don't see how I can view those notifications. When I start Backups or the Software Manager no notification is shown.
Press super + m and you get to the menu you need. You can see/read the messages and delete them.
Thank you, @DeZett. Meanwhile I have found another way: click on the date/time display in the center top of the screen to get to the same menu as with super+m.