Now it works, nevertheless it still is (too) short, because you are using a soon-to-be insecure key size:
https://www.gnupg.org/faq/gnupg-faq.html#default_rsa2048
"In 2010, France’s Agence Nationale de la Securite des Systems d’Information stated they had confidence in RSA-2048 until at least 2020."