Unable to sign in using a passkey on amazon.co.uk on iPhone/iPad

Hi,
I have successfully added a Passkey into my existing 1Password Amazon login using my Mac and I can login and out to my hearts content on the Mac. The Passkey login is showing as synced to my iPad and iPhone 1Passwords. When I try to login using my iPad, the option to use a passkey exists, but when I click it I get a QR code asking me to scan it with another IOS device. When I do this with my iPhone I get "There are no matching passkeys saved in 1password" and on my iPad I get a message"Use your other device to choose a passkey"
So, I'm stuck. Any ideas.
I'm on the latest Mac, iPad, iPhone and 1password versions, as at today's date.

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