From Main Menu level to Game Level but Game level not working

Hi I would highly appreciate if someone could explain what is going on with my game. I created a simple Main Menu which has its own GameMode class with no pawn attached to it, as well as WorldSettings put to that GameMode. When I click the play button, the game level opens up but nothing works. ( I have a AI system that spawns a turtle shell in a random spot and follows the player). When I click play from the Game level itself and not from the Main Menu level, everything works fine. I also have some buttons which re-open the Main Menu after winning the game, and if I click Play, then suddenly everything works fine. The issue comes up when I try to start playing from the Main Menu Level.