How can overlapping 36.8937 cM (from 11,551,254 to 48,458,402) and 82.9541 cM (from 12,460,601 to 74,135,725) matches on Chromosome 18 not match each other?
On GEDmatch, I compare Alice to Bob and get 36.8937 cM and then compare Alice to Charlie and get 82.9541 cM, but comparing Bob to Charlie gets zero matching. Alice, Bob, and Charlie's paper trail show they all meet up at the same set of parents for their MRCAs.
I understand that because these kits are not phased and two values are at every position, you can get false positives, but given the very long length of 12,460,601 to 48,458,402 shouldn't that be near zero probability to be a false positive?
Does this suggest some kind of corruption in the DNA test data or blank spaces in the data? What would explain such a long false positive?