If I launch my lobby from Server Window, Remote Window goes to Game Default Map. (Testmap_Onur in my case). But if I launch lobby from Remote Window, this doesnt happen. I double check that there are no code for it to go that map and I dont remember this happening on 4.16 (I did amost all of my tests in 4.16 so I am sure would have noticed it.) You can see related part of log.
LogNet: Browse: /Game/Maps/Lobby??listen
LogLoad: LoadMap: /Game/Maps/Lobby??listen
LogNet: World NetDriver shutdown IpNetDriver_105 [GameNetDriver]
LogNet: DestroyNamedNetDriver IpNetDriver_105 [GameNetDriver]
LogNet: UNetConnection::Cleanup: Closing open connection. [UNetConnection] RemoteAddr: 127.0.0.1:64062, Name: IpConnection_93, Driver: GameNetDriver IpNetDriver_105, IsServer: YES, PC: MainMenuPC_C_1, Owner: MainMenuPC_C_1
LogNet: UNetConnection::Close: [UNetConnection] RemoteAddr: 127.0.0.1:64062, Name: IpConnection_93, Driver: GameNetDriver IpNetDriver_105, IsServer: YES, PC: MainMenuPC_C_1, Owner: MainMenuPC_C_1, Channels: 11, Time: 2017.08.21-17.44.05
LogNet: UChannel::Close: Sending CloseBunch. ChIndex == 0. Name: [UChannel] ChIndex: 0, Closing: 0 [UNetConnection] RemoteAddr: 127.0.0.1:64062, Name: IpConnection_93, Driver: GameNetDriver IpNetDriver_105, IsServer: YES, PC: MainMenuPC_C_1, Owner: MainMenuPC_C_1
LogExit: GameNetDriver IpNetDriver_105 shut down
Cmd: MEM
LogMemory: Platform Memory Stats for Windows
LogMemory: Process Physical Memory: 3721.20 MB used, 3952.67 MB peak
LogMemory: Process Virtual Memory: 4867.26 MB used, 5082.39 MB peak
LogMemory: Physical Memory: 7562.97 MB used, 8641.72 MB free, 16204.69 MB total
LogMemory: Virtual Memory: 6216.05 MB used, 8641.72 MB free, 134217728.00 MB total
Allocator Stats for TBB: (not implemented)
LogAIModule: Creating AISystem for world Lobby
LogLoad: Game class is 'LobbyGM_C'
LogTemp: Display: ParseSettings for GameNetDriver
LogTemp: Display: ParseSettings for IpNetDriver_107
LogTemp: Display: ParseSettings for GameNetDriver
LogInit: WinSock: Socket queue 131072 / 131072
PacketHandlerLog: Loaded PacketHandler component: Engine.EngineHandlerComponentFactory (StatelessConnectHandlerComponent)
LogNet: GameNetDriver IpNetDriver_107 IpNetDriver listening on port 7777
LogWorld: Bringing World /Game/Maps/UEDPIE_1_Lobby.Lobby up for play (max tick rate 60) at 2017.08.21-20.44.06
LogWorld: Bringing up level for play took: 0.001091
LogGameMode: FindPlayerStart: PATHS NOT DEFINED or NO PLAYERSTART with positive rating
LogLoad: Took 0.343000 seconds to LoadMap(/Game/Maps/Lobby)
LogNet: Warning: Network Failure: GameNetDriver[FailureReceived]: Host closed the connection.
LogNet: Warning: Network Failure: GameNetDriver[FailureReceived]: Host closed the connection.
LogNet: NetworkFailure: FailureReceived, Error: 'Host closed the connection.'
LogNet: UNetConnection::Close: [UNetConnection] RemoteAddr: 127.0.0.1:7777, Name: IpConnection_92, Driver: GameNetDriver IpNetDriver_106, IsServer: NO, PC: MainMenuPC_C_0, Owner: MainMenuPC_C_0, Channels: 11, Time: 2017.08.21-17.44.06
LogNet: UChannel::Close: Sending CloseBunch. ChIndex == 0. Name: [UChannel] ChIndex: 0, Closing: 0 [UNetConnection] RemoteAddr: 127.0.0.1:7777, Name: IpConnection_92, Driver: GameNetDriver IpNetDriver_106, IsServer: NO, PC: MainMenuPC_C_0, Owner: MainMenuPC_C_0
LogNet: Warning: Network Failure: GameNetDriver[ConnectionLost]: Your connection to the host has been lost.
LogNet: Warning: Network Failure: GameNetDriver[ConnectionLost]: Your connection to the host has been lost.
LogNet: NetworkFailure: ConnectionLost, Error: 'Your connection to the host has been lost.'
LogNet: NotifyAcceptingConnection accepted from: 127.0.0.1:64062
LogNet: NotifyAcceptingConnection accepted from: 127.0.0.1:64062
LogNet: Browse: /Game/Test/Test_Maps/Testmap_Onur?closed
LogNet: Failed; returning to Entry
LogLoad: LoadMap: /Game/Test/Test_Maps/Testmap_Onur?closed
LogNet: World NetDriver shutdown IpNetDriver_106 [GameNetDriver]
LogNet: DestroyNamedNetDriver IpNetDriver_106 [GameNetDriver]
LogExit: GameNetDriver IpNetDriver_106 shut down