Single Sign On (SSO) in SAP B1 9.1 PL6

I configured the SSO in SAPB1 9.1 PL6 with the possibility authorize also in SAPB1. Users can log on using both SAP Business One user accounts and Windows domain accounts. However, users who do not have the configured SSO, after unchecking Log on with the Current Domain User checkbox not see any database. If I manually type the name of the database then I log in using the user SAPB1.
Is this normal behavior? When I uncheck Log on with the Current Domain User checkbox, that must not appear all databases to which I have access to? How it works on your systems?

Thank you in advance for your answers?