I have a Surface Pro 4 with a cover keyboard that has stopped working. It was working in January while we were travelling. When we returned home, I only used the Pro 4 with its docking station. I had occasion to use it off the docking station the other day, and the keyboard is not working. I looked under keyboards in device manager and there is no surface cover type listed. There are four HID keyboard devices listed. I looked at their properties and none of them seemed relevant and they were all working properly.
Booting up to the UEFI shows a Type Cover listed there; I disabled, rebooted, and enabled it with no result.
I'm running all the latest updates on Windows 10. I don't know how to check for latest on firmware.
I have also tried the 2-button shutdown and startup.