Unfortunately we are not logging the xp on retirement, only the level. The "level up" message is generated by the client, so there is a very small/unnoticeable delay when you see it and when it is actually stored in the database. But it is possible something went wrong on the database side with the level up and you have to wait for the next tick.
The latest database backup we have before you retired is a few hours old and you had close to 17 million xp, i can revert to that if you can get the heirloom point back which you already traded.