I have no doubt at all that it is another of the many glitches that is plaguing ebay at present.  The responders here have been fielding queries for weeks about some very serious problems but ebay either denies that they exist or says that they are being fixed.

If you have a look around the boards you will see that duplicate emails are just a minor inconvenience compared to some of the problems being reported.

Just be patient.....eventually something will be done.....at least we hope so.