crc: Unable to enter pull-secret when using MinTTY during start command: 'Incorrect Function'

On a Windows laptop 10 Pro After running:

crc setup
crc start -c 7 -m 13000 --log-level debug

I get as far as the prompt for:

level=info msg="Does the Hyper-V virtual switch exist"
? Image pull secret [? for help]
level=error msg="Error ocurred: Incorrect function"

then it exits without giving me the chance to enter the secret

I am guessing I need to create a network interface for hyperv, but as I can’t set the name (unlike minishift) what does it need to be called?

BTW: this worked fine on my iMac