Hello arkadiy748,
Thanks for reaching out to the Apple Support Communities. From your message it sounds like you're not seeing any incoming calls from unknown callers. You are only receiving calls from those who are in your Contacts list.
Based on this information, check to see if the setting for Silence Unknown Callers is turned on. This prevents any calls from numbers which you haven't been in contact with and aren't saved in your contacts from appearing on your screen. This article will tell you more about it: Detect and block spam phone calls.
If you don't have this setting enabled, also follow the steps under, "Set up an app to filter and detect spam calls," to see if there are any apps that could be assisting in filtering these unknown callers.
All the best.