I managed to do it by creating a session using the “Create Session Advanced” node (dedicated server activated, presence deactivated, LAN deactivated) and connecting the client player controller to the “Join Session” node shown above. This caused some Steam tag overflow error at first, but I fixed it using this workaround. There still is an “invalid player state” error which doesn’t have an effect due to the “Create Session Advanced” node not requiring a Player Controller input on a dedicated server.