We've been using a number of smart groups created via the search builder and from time to time, the smart group criteria disappear or are changed. For instance, we had five similar smart groups based on membership in five different groups with a certain contact type. At some point, the criteria changed for all five smart groups to membership in group 0.
We've had occasional similar issues for years, with no obvious trigger for the change. Does anyone have any idea what might be happening? Has anyone else had the same issue?