### Godot version

v4.1.rc1.mono.official [1f9e540f1]

### System information

Godot v4.1.rc1.mono - Windows 10.0.19045 - Vulkan (Forward+) - dedicated NVIDIA GeForce GTX 1660 Ti with Max-Q Design (NVIDIA; 31.0.15.3179) - Intel(R) Core(TM) i7-9750H CPU @ 2.60GHz (12 Threads)

### Issue description

When NavigationAgent3D is instantiated at runtime and added to the scene tree, invisible/impassable obstacle is added at the global origin position (0, 0, 0).

### Steps to reproduce

1. Run attached MRP
2. Click with `left mouse button` at the world origin to make agent walk
3. Click `space` on your keyboard to instantiate NavigationAgent3D
4. Click left mouse button to walk through world origin position again
5. Player gets stuck on obstacle at the world origin position

https://github.com/godotengine/godot/assets/8630984/fc9b32fb-25cb-46d6-9a98-ff299e2c0b1c



### Minimal reproduction project

[MRP.zip](https://github.com/godotengine/godot/files/11910363/MRP.zip)

ERR_FAIL_COND_V_MSG(agent_parent == nullptr, 0.0, "The agent has no parent.");
	return agent_parent->get_global_position().distance_to(target_position);
}
bool NavigationAgent3D::is_target_reached() const {
	return target_reached;
}
bool NavigationAgent3D::is_target_reachable() {
	return target_desired_distance >= get_final_position().distance_to(target_position);
}
bool NavigationAgent3D::is_navigation_finished() {
	update_navigation();
	return navigation_finished;
}
Vector3 NavigationAgent3D::get_final_position() {
	update_navigation();
	const Vector<Vector3> &navigation_path = navigation_result->get_path();
	if (navigation_path.size() == 0) {
		return Vector3();
	}
	return navigation_path[navigation_path.size() - 1];
}
void NavigationAgent3D::set_velocity_forced(Vector3 p_velocity) {