Dedicated Server

when i play the game with 2 or more clients with dedicated server checked when i play on client the “windows” loses its focus on the first player that joined so it will run in lower frame rate . the problem is when i play with client things that doesn’t related to server works fine but for example when i get in to a vehicle and the movement of the vehicle is replicated the vehicle moves at the frame rate of server (the things is its OK when client moves around or stuff like that)

1- help me with having focus on both windows
2-how can i stop Being affiliated to server with stuff like vehicle movement (just like my player movement)