PhotonNetwork.SetMasterClient() not working

Hello,

I am trying to understand why the Master Client doesn't switch when I call SetMasterClient.

I have two Android mobile devices. They run the same code apart from one bool variable which I use to distinguish between the two.

I tell one of the two to set itself as master client by doing a check on that bool variable but although SetMasterClient returns true, the network doesn't acknowledge the switch

if (_Kwesi != null)
{
            bool _success = PhotonNetwork.SetMasterClient(PhotonNetwork.LocalPlayer);

            Debug.LogWarning($"Local player Nickname: {PhotonNetwork.LocalPlayer.NickName}, Actor Number: {PhotonNetwork.LocalPlayer.ActorNumber}, IsMasyer: {PhotonNetwork.LocalPlayer.IsMasterClient}, UserID: {PhotonNetwork.LocalPlayer.UserId}");

            if (_success)
            {
                Debug.Log($"I have assigned the master client to the !autoconnect player. Outcome: {_success}");
                Debug.Log($"AM I THE MASTER CLIENT? =  {PhotonNetwork.IsMasterClient}"); //THIS ALWAYS RETURNS FALSE even if it should have switched
            }
        }
        else
        {
            Debug.LogError("Failed to assign master client to Kwesi");
        }
}

I also tried to turn this into an RPC which I call on the master client from another client as I thought maybe only the master client can force a mnual switch but the result doesn't change.

What am I doing wrong?

Many thanks!