Disclosure: I work for AgileBits, makers of 1Password Chrome on iOS is a unique situation. We offer two things for developers that integrate with 1Password:

Disclosure: I work for AgileBits, makers of 1Password Chrome on iOS is a unique situation. We offer two things for developers that integrate with 1Password: 1. Native application integration. The idea here is that apps that offer a login to their service/site can pull the username and password from 1Password, then insert it into their native UI controls and sign the user in 2. Web view integration. The idea here is that the developer pass us the web view as part of the process and we handle the filling. Chrome is using option #1, so what they do is give us the URL, we provide the list of Login items, and then they take the username and password and provide the filling. For the filling parts we have absolutely no control over this in Chrome. Any filling related bugs are completely on Chrome to fix. If they used our web view filling option you'd have consistently the same filling behavior as 1Password does in Safari on iOS. Sorry you had this experience though. Unfortunately we can't really do anything about it except say we understand your pain. We spent a lot of time and effort getting our filling systems to work as well as they possibly can and when users report issues in Chrome we have to send them off to Google to report those and get them fixed. Kyle AgileBits