Hey, founder of Hanko.io here, we run passkeys.io. That behaviour is not intended. We've recently changed the demo to require authenticator attestation on passkey creation, that may have an impact on authenticator selection. But a quick test on my system (macOS, Chrome) resulted in the 1Password UI intercepting the "Create a passkey" flow - as expected. It would be awesome if you could help us understand why your experience is different.
With that being said, we are not happy with how password managers have implemented passkey intercepts, but ultimately that's a decision the user can make, as it can be disabled in the browser extension settings.
