Problem logging in to Gmail in iOS Safari

I’ve just migrated from an iPhone 8 to an iPhone 13 mini and I can’t get 1Password to login to my mail accounts in Gmail in Safari, which had worked perfectly well before. 

When I choose an account from the Gmail page I then get the message: “You don’t have any passwords for this app. You may be able to choose a password to use from the app below” and there’s 1P below, ticked, and a Continue button. Face ID (new to me for this phone) then takes me into my vault in 1P, but there’s nothing there, just a “Create new item” line. But I know my login items for Gmail are intact in 1P. 

It’s a bit of an endless loop. Any suggestions?