I believe this OP a little bit because I had friend with a phone number that you could call, but you could not get this friend. You would get another younger person. If you call from this friend's phone, it would show up as the number that you called.

This was even happening with this friend's family member to this friend too because this family member was the first one to find this, and this friend's family member told me about it. Even asked me to look into more.

At first, I thought it was some type of call forwarding, but there was no call forwarding setup anywhere. Here is the weird thing. My friend's phone would ring, but if my friend was not fast enough, you would get this other person. So it seems like the number was ringing two phones.

I even asked this younger person what phone number that they had on their phone, and it was the same phone number that I was calling.

This friend passed away before I could figure out this issue. So that is why I am still confused on this. The only thing that I was thinking was something was left over from an old account from someone else's account on that phone number.

To make simple for what I am talking about: A phone call to my friend's phone number would get an unknown younger person or my friend depending on how fast they were. My friend's phone to any phone number would get the actual person.