Why does Google passkey authentication halt with Safari 16.6.1?

I have already created a passkey for my Google account and assigned to the AppleID Keychain. Thus I assume that my BigSur machine has access to the passkey. Google indicates that Safari 16.1 is the minimum for Google passkeys. Google also indicates it Ventura (MacOS13) is necessary to CREATE the passkey. My Monterey (MacOS12) machine has AppleID Keychain access and has successfully authenticated via Passkey through Safari. Therefore, I think it reasonable to expect that I can do the same on Safari 16.6.1 running on BigSur 11.7.10. Why does authentication hang as shown in the screenshot? Any troubleshooting suggestions are appreciated. Thank you