If you find that RDP disconnects after a few seconds, it might be because of the RDP Client settings. I found that RDP was disconnecting after a few seconds on one client but not another. I fixed this by editing the properties of the RDP connection on the client to not map any local resources in the RDP connection. After deselecting the option to map the clipboard and printers, my RDP connection no longer disconnected after a few seconds 🙂