How to synchronize the player spawning over the network?

I want to synchronize the spawning of the player characters over the network because I always run into this issuse:

I connect to the game with the first character and this one creates a RandomRoom.
Now I want to spawn in the second characterand this second character joins the Room that has been created by the first player.
BUT when I join with the second character, he can´t see the first character, which joined before him.
However the first character can see the second character that joined.

Here is the code that I use to spawn in the Characters:
using UnityEngine;
using Photon.Pun;


public class SpawnPlayerCharacter : MonoBehaviour
{
    public static SpawnPlayerCharacter SPC;
    public GameObject playerPrefab;

    private void Start()
    {
        SpawnPlayer();
    }

    public void SpawnPlayer()
    {
        playerPrefab = CharacterManager.CM.allCharacters[CharacterManager.CM.mySelectedCharacter];
        //float randomX = Random.Range(+80f, -80f);
        //float randomZ = Random.Range(+80f, -80f);
        PhotonNetwork.Instantiate(playerPrefab.name, new Vector3(10f, 502f, 20f), Quaternion.identity);
    }
}