I'm using Pixel 7 Pro and turned on the new Passkeys feature in my Google Account two days ago. I can login to Google Account using Passkey on my Windows PC (via Windows Hello/physical security key) and iPad, but not on my Pixel phone.
When I use Edge or Chrome on my phone, it will still ask me to enter password + 2FA (the old way). But when I use my PC or iPad, it will show the Passkeys page and I can login instantly.
I understand that Passkeys are supported on Android and I was able to test it on passkeys.io or webauthn.io website, which worked perfectly on my phone.
Another strange thing is that when I try to login to my Google Account on my phone using password and it asks for 2FA, I won't be able to use my physical security key (it will say "Not supported on this device or browser" on the security key option. Only OTP, Tap Yes on phone, etc. will work)
Similarly, I have enrolled my physical security key with my company's Azure AD to sign in passwordlessly. On my PC, I can simply click "Sign in with Windows Hello or a security key" and use my security key to login without even having to enter my work email. But on my phone, this option will not appear and I'm forced to enter work email + password and approve the login via Microsoft Authenticator app.
I thought I knew about all these modern authentications like FIDO2, WebAuthn, Passkeys, etc. but it seems like I'm missing out on something.
I would like to know why Passkeys don't always work on my phone?
Thanks.