Just went to the Apple ID page and it appears that the icon for 1PX is super small and doesn't format well in the text box. I think it may be due to the fact that when you enter a username, a password field appears below it and moved that input upwards on the page.
1Password Version: 7 (latest beta)
Extension Version: 1.6.6
OS Version: 10.13.4
Sync Type: Not Provided