DNA Comparison 1 marker diff = 4 Surnames

[J Yarbrough]

I used Family Tree DNA's "Find Genetic Match adn set the Distance for 1 Marker. The results had mine and three other surnames.
One of these other names responded and is confused as I am regarding the close match.
One Surname most distant ancestor was from Ireland.
Another, listed Scotland
The third listed England.

Is this result common?
My results do match one other with my surname but is my DNA test valid?

[J Yarbrough]

I have checked some of the DNA surnames that had a ZERO distance on the surname tht did not matche me on 11 markers and it had 8 surnames matching it.
Something is wron or needs aexplanation.
Has anyone else checked the Genetic distance on their reuslts?