Lobby chat

My mic is on and the settings are good but I cant hear my friends in the lobby and they cant hear me and then when I go to the character selection screen I can hear them and they can hear me I dont know whats going on but can you please fix this issue and im lagging to like i dont lag until I get a guy half down and then they dissappear and then reappear and im down i dont know whats going on please I would like both of these matters resolved