I don't know what happened. I turned my Surface Pro 4 on the other day and the type cover is dead. No lights. No response. No indication that it's working at all. I rarely take my surface anywhere.
This started on July 9th 2018. My system information is below. I've gone through all of the steps in the "Troubleshoot your Surface Type Cover or keyboard" page. I've tried to manually download and install the latest firmware and drivers from the "Download firmware and drivers for surface" page. I picked SurfacePro4_Win10_16299_1801701_1.msi. My device manager does not show the "Surface Touch Cover Filter Device" under keyboards or anywhere. It only shows the HID keyboard and cannot detect my type cover. The type cover is completely unresponsive. Also, my windows updates are completely up to date. I've provided the links to the troubleshooting pages I used below.
AGAIN, WTH
Troubleshoot your Surface Type Cover or keyboard
Download drivers and firmware for Surface