Mine, just to let you know, it's very normal for this to happen, especially if you've ever rezzed something on a mainland region. Mainland regions get reclaimed when someone gives one up, and then later someone else buys it and it is reused. In other cases, regions may be renamed or moved depending on the new owner's wishes. In fact Xocotora is one of the many regions Biker now owns on the mainland.
Also, it's definitely possible for prims in objects rezzed to be ignored for a very long time, especially if they fit the environment. In this case a flag pole and flag? That sounds reasonable that it may not be returned for a very long time, especially on a mainland region. I checked, and auto-return is indeed now enabled in that parcel where the flag pole was.
If you want, it can be arranged for all remaining items owned by you to be returned now so that this never happens again.