Help me. Unreal Engine 4

Hello, I’m one step away from creating my game. However, I have a problem. I translate:
I have 2 maps, one is the whole map (FirstMap). The second is the main menu through which I run (FirstMap), but (FirstMap) was running without an actor. I fixed it but now actor is not chasing me or box collision is not working and is not walking on the map. As if the nav mesh bounds volume is missing on the map. But it’s not because of that. I do not know why this is so, please help.