Internal CMS message shows up on login screen

Reproduction path:

• login into the console as admin
• login to the CMS in a different tab in the same browser with the same user
• in the Admin / Groups panel create a new group
• log out of the CMS: a message about the creation of the group appears on the login screen, see attached screenshot

My guess is that an info-message-bar or -panel is missing that should have picked this message up (see screenshot). If that is in place, the message will show up there, and does not bubble up to the login screen.
The same effect appears after creating a new user.