Navigation system for second client is missing

Hello. I’m running two clients. In my code I have

UNavigationSystem* const NavSys = GetWorld()->GetNavigationSystem();

This is from top down template. And this returns NULL.
Also, if I’m running dedicated server same problem arises on both clients.

Same problem here: basically if you start the TopDonwBP project with two clients, only the “server-character” will be able to walk around. And if you start it with dedicated server no client character is able to move. Any ideas why?