Game Mode Not Changing...

I have created two game modes: GameMode and LobbyMode. In LobbyMode I have a spectator spawn and I create a menu blueprint widget which handles the various menu functions for me. I also prevent mouse looking and movement in this mode. The GameMode works like a normal game mode … no menu but a HUD.

I have two levels, one Lobby and one Arena. I have ensured that the Lobby is set up to use the LobbyMode and the Arena is set up to use the GameMode. Now if I launch the Arena - the correct GameMode runs, if I launch the Lobby - the correct LobbyMode runs.

If however I click on play in the LobbyWidget and it loads the Arena level … the game mode stays as spectator and doesn’t transition across to the GameMode.

Am I doing something wrong?
Is there any help somewhere on this subject that can hopefully lead me in the right direction?

I thought that I was doing it the correct way … with each mode having its own HUD and Controller … but maybe I am totally missing the point here. Any help will be greatly appreciated.