Solved Need help with spawning NMS mob

I've made a custom zombie but it didn't seem to spawn in
Here's my code

Code:

public class CustomZombie extends EntityZombie{

public CustomZombie (net.minecraft.server.v1_16_R3.World world) {
super(EntityTypes.ZOMBIE, world); this.getWorld().addEntity(this, CreatureSpawnEvent.SpawnReason.CUSTOM);}

public CustomZombie (org.bukkit.World world) {
super(EntityTypes.ZOMBIE, ((CraftWorld) world).getHandle()); this.getWorld().addEntity(this, CreatureSpawnEvent.SpawnReason.CUSTOM);}

public void spawn(Location location) {
this.setPosition(location.getX(), location.getY(), location.getZ());}
}

When I run the spawn() method, I tried to debug by sending
String.valueOf(customZombie)
and it seemed to be working, it showed the name of the world, and the location of the zombie, but no zombie spawned in

Any help is appreciated

EDIT: I somehow fixed it, no idea how but it works nonetheless