When you look in Device Manager does the Type Cover show an Exclamation Mark next to it?
Shut down the RT completely...then hold the Volume Rocker Down and press power keeping the rocker pressed until the Surface Logo comes up, exit the UEFI Screen, allow to reboot and see if it detects the Cover.
I can't even see it in devices, it doesn't show up at all! Yes I updated yesterday.
Update the driver - choose from list select Keyboards then select HIDI have updated the driver but still can't seem to get it to work. It is still showing up as I know device under other devices.