Error with short-lived-cert

I have been evaluating Cloudflare access to implement in our company and I run it this issue and I'm a little bit lost. After reading several pages of documentation and looking around on the web I could not find a fix.
I follow the guide to use short-lived-cert but it still asks me for password and gives me the error bellow, i tested client from Windows Mac and Linux
If I generate a local regular key and add to origin authorized_keys it works fine.
If use my my local generated Cert and add to sshd_conf it works fine.
0: Bad Request. Invalid issuer. Currently only cloudflareaccess subdomains are supported.

Any idea what it can be?
I don't believe it's a bug.