Samsung aggressively blocks spam by default.
To physically unblock the numbers:
But the wiser question is not how to unblock unknown numbers, but when . Use temporary unblocks for deliveries. Use voicemail transcription for peace of mind. And remember: If a call is truly important, they will leave a message. You do not need to answer the ring to answer the call. how do you unblock unknown numbers
If you're not using a standard Android or iOS device, or if the above steps don't work for you, try these alternative methods: Samsung aggressively blocks spam by default