Multiple accounts with passkeys for the same website

I know that I am replying to a kind of old post here, but I came across this thread while experiencing some frustrations of my own and felt compelled to chime in. I, too, have been experiencing a situation on iOS similar to what @shadowplayer has described. It is seemingly impossible, at first glance, to use multiple passkeys on a single domain with the 1Password app.

TL;DR I found a trick which allows you to use all the passkeys you registered on a domain as expected.

I say "seemingly impossible" because the situation is not so cut and dry. When registering and saving a new passkey for a given domain, there appears to be no problem with creating multiple items for a single domain. It looks like it all works just as one would expect, based on experience with traditional username and password pairs. However, when it comes time to actually use one of the passkeys to log in, the flow one is presented with is, shall we say, "incomplete" for lack of a better term, Only the very first passkey registered on the domain is given as a possible option. This is in stark contrast to how the iCloud Keychain presents one with a list of all registered passkeys for a given domain, from which the desired one can be selected.

It would seem, though, that this is a regression of some kind in the 1Password app. This behavior does not seem to be an intentional design choice by the developers. It is possible to get all the passkeys for a given domain to show up as expected.

The trick to achieve this, I found, goes as follows:

(1) Create your passkeys for the domain
(2) Verify they have all been saved as separate items in your vault (make sure you did not accidentally overwrite any of them by choosing to update an existing item instead of creating a new when you were carrying out the registration process)
(3) Open the 1Password app and select the item in your vault which corresponds to the first passkey you created for the domain
(4) Proceed to edit that item
(5) To the right of the website field, there is a button for Autofill behavior, tap it
(6) Select the option Never fill on this website and tap Done
(7) Tap Save
(8) Back in Safari, navigate to the login page for the domain in question
(9) Proceed with the passkey authentication flow for the site
(10) Observe that all the passkeys you had registered on the domain in the 1Password app are now selectable and work as expected

You can now go back and revert the changes you made, regarding the Autofill behavior, to the first item containing a passkey for the domain. The (now) correct and expected behavior in the passkey authentication flow should remain. But if you add any more passkeys for the domain in the future, the procedure described will need to be repeated to get them to show up as expected.

I know that was a lot, but hopefully this post helps at least just one other person who is as frustrated as I was.

iPhone Model: iPhone Xs Max
iOS Version: 17.2.1
1Password App Version: 8.10.23