Hi!
It looks like GnuPG 2.2.23 is not working correctly - I reproduced the error on my Windows 10 setup. Updating to GnuPG 2.2.25 helped (Gpg4Win 3.1.14). Please try it and let me know.
Edit: in case GnuPG would not see the card due to OpenSC blocking the access on Windows, this command should help:
net stop scardsvr
Edit: other issue with this GnuPG release: How to reset NitroKey Start? (GPG 2.2.23).