On my mother's side of the tree we have two second cousins, one is a confirmed 2nd cousin the other is who we are trying to figure out, this person was adopted. They both show DNA match for me as a second cousin. They do not come up as a match for each other. Can someone help what may be missing. Same side of the family, they should show as a match too. Is this some kind of error with AncestryDNA. Any useful feedback or ideas would be greatly appreciated.