Jim, I looked at GEDmatch and saw that we share about 4.4 cM which must be why our match disappeared. The mB is 5.5 which explains the initial match based on the old rules. Your match with Mom is far stronger....11 cM and 12 mB plus a secondary match on a second chromosome. So it looks as if the initial mB algorithm was picking up some genuine matches. I need to remind myself that 'lost' matches can be from wonky segments and/or the change to cMs from mBs.