@drashti_m Visit Number is a lifetime metric, that wouldn't work properly in this context... People who had "Visit Number 1" 10 years ago would no longer even be able to see "visit number 1" in the 2-3 year truncated data....
@bsq what you have looks correct. You have a rolling date (Last 13 Full Months) and Visits greater than or equal to 12 (at the Visitor level)
I did you exact segment and its working for me, or at least the result looks fairly realistic (comparing my segmented data to my unsegmented shows a significant difference).
How did you identify the "visitors who made only 1 visit" in the last 13 months.... If you are tracking your ECID (this is what I checked, and I do see users with 1 Visit), it's possible that at some point, the user's ECID from different places has been stitched in the Adobe Backend? The ID as recorded would be values as set, but I would assume that there is additional ECID / Visitor Stitching happening (particularly when using the AppendVisitorIdsTo feature, which will override the ECID on the destination with the passed ECID... Adobe must be doing additional User Stitching behind the scene to take those 2 ECIDs and to merge them to one record...
I still believe that the way you built your segment would be the correct way to build this.