Upstate1618 No, I'm not talking about Ente. I'm talking about Proton. Let me explain it to you more precisely:
On Vanadium, log in to your Proton. In Settings-Account and recovery, add a security key here with allow platform checked. Use your GOS as the security key and the procedure would fail in the end which is not expected. I'm contacting with Proton about this.
I confirmed to you earlier that I can reproduce this issue. I now get the impression that you are asking me to reproduce this issue one more time. If so, it would be beneficial if you stated that request explicitly, perhaps by quoting my relevant post.
Upstate1618 On Edge for PC, you can create a passkey for Proton on Proton Pass/Bitwarden. But you cannot authenticate it on Vanadium. This is expected and intended. You said you can authenticate it on Vanadium which is impossible.
I don't know what to tell you, other than the fact that it works completely fine for me. It is not a passkey that I generated using the steps from my first post in this thread; I deleted those prior to testing saving a passkey for my Proton account in Edge, then succesffully signing in with that passkey as MFA on account.proton.me in Vanadium on GrapheneOS. I have tested this four times just now.
From Edge on Windows: https://ibb.co/F7Q6Rtr
From tapping 'Authenticate with security key' on account.proton.me from Vanadium: https://ibb.co/Sxj5CX9
(Apparently Android doesn't allow you to screenshot both the browser page contents and the passkey sign-in flow at the same time; that's why the background in the second screenshot is blacked out).
Edit: I will mostly not have access to a computer for the next three weeks, so will be unable to assist with this until after that time.