I am a very beginner and i honestly have no idea why but the the shadows disappear once i reach some area.

so here is a bit about my scene: it's a loaded/unloaded chunk based world generator with perlin noise and as soon as a chunk is loaded it's physics is loaded and it has castShadow as true, also it uses MeshStandardMaterial, but after a few blocks the shadows just disappear.

Any idea how to fix this? i tried moving the lights along with the character but the shadows still disappear....