I know this is probably outdated, but leaving it here, just in case this is helpful to anyone else having this problem:
This is common especially after a factory reset. If you can't use your Surface Keyboard during the initial setup, use an external keyboard.
- You can use a generic USB C hub, (I have an Acer 0DK390 9-in-1), and a generic Kensington keyboard probably less than 10 dollars.
- Plug your USB-A keyboard into your USB C hub, and it works right out of the box, no configuration needed.
- At least this way, you can get past initial setup, get a network, and get the updates and drivers necessary to get yourself going from there.