you might be getting your modes mixed up? export mode is for managing your library and exporting to USB devices to plug them into an XDJ to play from without needing to connect to a laptop. If you want to connect/link your XDJ to a laptop and play the music on that laptop directly you need to change the RB mode to performance mode. If that's not the issue and you are already in Performance mode it might be the firewall on your laptop needs to be turned off for RB
George