1. Go to Admin and Settings
2. Go to More - Click Contact Merge

You'll get duplicates here if their First Name, Last Name, AND Email Address are all the same. I got ZERO when I clicked here.

I'm setting up a duplicate rule that looks for First Name, Last Name and not including email.

This is the record set designed to look just for First Name and Last Name. There is already one that uses the email too, but I saw that some of your duplicates have DIFFERENT emails.

You can find Duplicate Record Sets under the Waffle -- that nine dot thingy at the left side of the tab line.