Remove entities other than players when unloading a chunk

src/main/java/net/minestom/server/instance/Instance.java

@@ -105,6 +105,10 @@ public abstract class Instance implements BlockModifier, EventHandler, DataConta
     public abstract void loadOptionalChunk(int chunkX, int chunkZ, Consumer<Chunk> callback);
 
     /**
+     * Unload a chunk
+     * <p>
+     * WARNING: all entities other than {@link Player} will be removed
+     *
      * @param chunk the chunk to unload
      */
     public abstract void unloadChunk(Chunk chunk);

src/main/java/net/minestom/server/instance/InstanceContainer.java

@@ -313,6 +313,13 @@ public class InstanceContainer extends Instance {
             chunk.removeViewer(viewer);
         }
 
+        // Remove all entities in chunk
+        getChunkEntities(chunk).forEach(entity -> {
+            if (!(entity instanceof Player))
+                entity.remove();
+        });
+
+        // Clear cache
         this.chunks.remove(index);
         this.chunkEntities.remove(index);