I'm not sure if this is a GrapheneOS problem or a problem related to the account. I thought I'd have better luck posting this issue here than elsewhere.
I had a yubikey for my Google account, and because I was not able to add new keys, I removed it with the hope it would fix the problem. Unfortunately I'm now in a situation where they need 2FA, I removed that, now I need to use a phone number from now on. But beside the point.
Whether I use a desktop browser, or Vanadium, or manage my account through Play store, I cannot create new passkeys or add security keys to the account. When I go to Account > Security & sign-in > Passkeys and security keys > create a passkey / Use another device, I get this error popup
Something went wrong
We weren't able to save your changes. Return to your account settings, and try again.
I attempted to roll back my decision to remove my yubikeys, "this wasn't me" or whatever. That didn't work. Then I tried going back to the Play Store, and after having to relog, I got the message:
Couldn't sign you in
You appear to have no security keys registered to your account, and you won't be able to sign in.
To sign in on this device, go to myaccount.google.com/security on another device where you're already signed in. In your security settings, you can either: Register a new security key or choose another second step for verification.
Catch 22s all around with no way to add any security key or passkey. I tried various fixes like enabling Javascript JIT on Vanadium, giving Play Store requested permissions including Nearby Devices and Bluetooth, enabling NFC, inserting my yubikey via USB, and turning 2FA on/off again.
I don't know how to proceed. For the record I am not using Advanced Protection. Side note, I am going nuts with the amount of times I need to log in.