After solving #1, the map doesn't load correctly. It is ok when we drag the map horizontally, but not vertically. It seems when I want some tiles autoload in the top(i.e. drag the map downside), the tiles on the top will not be auto loaded, whereas the tiles in the bottom are loaded and vice versa.
Drag downside:
New tiles in the bottom are loaded:
After solving #1, the map doesn't load correctly. It is ok when we drag the map horizontally, but not vertically. It seems when I want some tiles autoload in the top(i.e. drag the map downside), the tiles on the top will not be auto loaded, whereas the tiles in the bottom are loaded and vice versa.
Drag downside: New tiles in the bottom are loaded: