Type cover/keyboard not working

My Surface Pro4 keyboard/ “type cover” stopped working. I tried it on another identical Surface Pro3 and it worked fine. I’ve been using a Brydge keyboard, which connects via bluetooth and that works fine, but when I snap on the magnetically attached keyboard that came with the Surface Pro it does nothing. It could be a connection problem, but I have cleaned the contacts to no avail. I at first suspected it was a glitch in a Windows update, but there have been many updates since then that did not correct the failure.

Anyone with experience with this please help. Thanks!