Unet duplicate playerControllerID's

Hey there, thanks for helping me out!
I have written a script that extends from NetworkManager that should look for matches and if it doesn’t find any, starts a match of it’s own.


The script detects matches, joins and creates, but when a client joins the server gets an error.
The Error I get when connecting with a client is:

“There is already a player at that playerControllerId for this connections.
UnityEngine.Networking.NetworkIdentity:UNetStaticUpdate()”


I have checked in Debug mode on the server and both playerobjects have networkID 0.
Does anybody know what to do about this?

My script:

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.Networking;
using UnityEngine.Networking.Match;

public class Lobby : NetworkManager {

	public int maxJoinAttempts = 5;
	public Canvas lobbyUi;

	bool isReady;

   
	public void ToggleReady () //this is called by a UI toggle
	{
		isReady = !isReady;

		if (isReady)
		{
			StartMatchMaker();
			StartCoroutine(FindMatch());
		}
		else
		{
			StopMatchMaker();
			StopCoroutine(FindMatch());
		}
	}

	IEnumerator FindMatch ()
	{
		for (int a = 0; a < maxJoinAttempts; a++)
		{
			//try to connect to a match
			matchMaker.ListMatches(0, 100, "", true, 0, 0, OnMatchList);

			yield return new WaitForSeconds(1);
		}

		OnFindMatchFailed();
	}

	public override void OnMatchList (bool succes, string extendedInfo, List<MatchInfoSnapshot> matchList)
	{
		matches = matchList;

		if (succes)
		{
			if (matches.Count != 0)
			{
				Debug.Log("Matches found");
				OnMatchFound(matches[0]);
			}
			else
			{
				Debug.Log("No matches found");
			}
		}
		else
		{
			Debug.Log("Could not connect to matchmaker");
		}
	}

	void OnMatchFound (MatchInfoSnapshot match)
	{
		Debug.Log("Connecting to match");
		matchMaker.JoinMatch(match.networkId, "", "", "", 0, 0, OnMatchJoined);
	}
		


	void OnFindMatchFailed ()
	{
		CreateMatch ();
	}

	void CreateMatch ()
	{
		matchMaker.CreateMatch("PlayerMatch", matchSize, true, "", "", "", 0, 0, OnMatchCreate);
	}
}

OK, so the problem turned out to be my coroutine “FindMatch” not stopping after joining.
It tried to connect to the same server again and again after already being connected.