By default, Kaspersky Who Calls blocks only incoming calls from numbers that you have added to your spam list. All other spam calls are tagged as SPAM! Users complained if the number is found in the spam databases, but the app doesn't block them. You can set the app to block all spam calls, or certain categories of spam calls, automatically.
To set automatic call blocking:
In this mode, for instance, you may miss an incoming call from a bank if its number is listed in the spam databases.
A complete list of categories is available only in the Premium version of Kaspersky Who Calls.