If anyone else runs in to this issue. Silly mistake on my part. You have the attestation object that needs to be ordered, but the public key is also a cbor map which needs to be ordered, and then Google will work.

Hey @codecomet I'm currently running in to the same problem you have listed. I have a passkey provider application that is working everywhere except for google. I can confirm on webauthn.me/debugger that my Attestation object is an ordered CBOR dictionary in the order stated in the answer above (I have also tried other orderings, just in case). I'm curious if you have found any other possible reasons for why google passkey creation would fail? All I get is a message saying "Something went wrong. We weren't able to save your changes." I've tried on safari and chrome. If I try from inside an application on my phone it says "A passkey can't be created on this device".. Even though my device is up to date and I can create passkeys everywhere else. Thanks for any help on this.