The bug

Map data from exploring a region is lost after zooming out the map using 8 paper.
This can be been seen best when the player is not in the area visible on the map.

Steps to reproduce

See attached screenshots for expected results

1. Craft 2 Empty maps (not copies) - e.g. a Map in Hotbar Slot 1, a Map in Hotbar Slot 2.
2. Use the Map in Hotbar Slot 1
3. Use the Map in Hotbar Slot 2.
4. Observe map data shown is identical for both maps. In the attached example, note for reference the village shown on the map.
5. Zoom out Map in Hotbar Slot 1 using 8 paper. Look at Map and observe map data is present.
6. Travel straight 300 blocks on X axis and 145 blocks on Y axis.
7. Observe that on both maps the player's location is shown as a white dot along the edge, indicating the player is outside of the maps' boundaries
8. Zoom out Map in Hotbar Slot 2 using 8 paper. Look at Map and observe map data is missing. EXPECTED: Explored section remains visible.
9. Return to original location. Observe that previously explored map data shown on this map reappears on Map in Slot 2.