Synchronizing the state of a complex Scene Object

Hello. I'm using Photon Unity Networking for my small maze game.
Feel free to give your opinion on every step of the process.

I will differentiate generating the maze (creating the theoric maze) and building the maze (instantiating the actual walls of the maze in the scene during runtime)

I want to generate the maze at runtime (so that it's different each game).
To generate it, I use a MazeGenerator (see attached)

using UnityEngine;
using System.Collections;
using System.Collections.Generic;


public class MazeGenerator : MonoBehaviour{

	private class Cell
	{
		public bool NORTH_WALL;
		public bool EAST_WALL;
		public bool SOUTH_WALL;
		public bool WEST_WALL;
		public bool VISITED;

		public Cell(){
			NORTH_WALL = true;
			EAST_WALL = true;
			SOUTH_WALL = true;
			WEST_WALL = true;
			VISITED = false;
		}
	}
	
	private int height;
	private int width;
	private int braidFactor;
	public GameObject wallPrefab;

	private int size;
	private Cell[] cells;
	
	public void Initialize(int hgt, int wdt)
	{
		height = hgt;
		width = wdt;
		size = height * width;
		braidFactor = (height + width) / 2;
		cells = new Cell[size];
	}

	public void Generate(){
		//Actual generation of the theoric maze, not important here I guess
		//It works because I succeeded in Building the maze locally
	}

	public void BuildBase(){
		//The ground and the external walls can be built locally, since they are always here
		}

	public void BuildWalls(){
		//This is just what I used to do, but it doesn't work
		//Instantiating too many walls with a photon view in the scene creates QueueIncomingReliableWarning
		/*
		for (int i = 0; i < height; i++) {
			for (int j = 0; j < width; j++){
				if (cells[ i * width + j].SOUTH_WALL){
					PhotonNetwork.InstantiateSceneObject(wallPrefab.name, new Vector3(j+0.5f,0.5f,i), Quaternion.Euler(0,90,0), 0, null);
				}
				if (cells[ i * width + j].EAST_WALL){
					PhotonNetwork.InstantiateSceneObject(wallPrefab.name, new Vector3(j+1.0f,0.5f,i+0.5f), Quaternion.identity, 0, null);
				}
			}
		}*/
	}
}

My problem is as follow :
If I generate the maze locally, of course every player will have a different maze and it's pointless.
If the master client generate a maze once (in OnCreatedRoom for exemple) I don't know how to pass the state of the maze (and particularly, the "private Cell[] cells" field) to the other players.

As you can see in the script, I tried using shit load of Photon.InstantiateSceneObject but it created a lot of QueueIncomingReliableWarning. Furthermore, I don't think having ~900 (depending on the dimension of the maze) walls as SceneObjects is a very good idea.

Then I tried to instantiate a single SceneObject to which I attach MazeGenerator, and which will contain the different methods to build the maze, but when I call BuildWalls() in the master client, it doesn't build the walls though it's a Scene Object.

Is there something I'm missing here ? It may be an error in the design and not in the code.