Your Shibboleth/Athens log in, logs you into the institutional account it is associated with. This will allow you access to all of your institution's holdings/subscriptions in SpringerLink.
However your Shibboleth/Athens log in, does not log you into a personal SpringerLink account. Because of this you will see the message "Not logged in' displayed in the footer of the SpringerLink webpage. This is expected behaviour at this point and doesn't affect your institutional access. You can check that you are correctly logged into your institution if you see the institution account name displayed.
For example before logging in you may see something like this:
Not logged in Unaffiliated 10.254.248.14
After logging in via a Shibboleth/Athens account: (for example: for Duale Hochschule Baden-Württemberg Heidenheim)"
Not logged in Duale Hochschule Baden-Württemberg Heidenheim (2000694000)Nationallizenz Zeitschriften-Archiv (3000137278)Nationallizenz Ebooks Medicine (3000137282)Konsortium Baden Wuerttemberg vertreten Albert Ludwigs Universität Freidurg (3000143214)Nationallizenz Lecture Notes-Archiv (3000262825)Nationallizenz Ebooks Chemistry and (3000262839)
If you have a SpringerLink account that wish to log into: you will need to log into this separately on the log in page. It is not in anyway connected to your Shibboleth/Athens account.