And for info, there was one pax on my flight who I was totally unaware of and to this day, I still don't know who authorised her or why I was not informed
The system would seem to hiccup from time to time. Boarded a QF 747 in MEL bound for LAX via SYD some 15 to 20 years ago to find someone else had my allotted seat. We both had boarding passes specifying the same seat. A check of the manifest by the FA (first class should it make a difference) and no mention of me. Alternative seat found and all was well. Would the flight deck have been advised?