The interface name uniqueness is case sensitive - user can create 2 interfaces with the same name but different uppercase/lowercase usage (for example "Abc" and "aBc").
As a result, one of these interfaces "hides" the other, and SmartConsole does not display one of them, but this interface still exists in the database.
Cause
The interface name uniqueness is case sensitive, thus "Abc" and "aBc" are two different names.