Not prompting to fill on kpl.org

When I try to login on https://books.kpl.org/iii/cas/login?service=https://encore.kpl.org:443/iii/encore_kpl/j_acegi_cas_security_check the extension does not prompt for me to fill in my saved item. Rather, it treats it as a registration form. Filling directly from the item in the popup works.

I am using Firefox.

Here are the collected page details (this form won't let me include the json file itself):

{
    "unparsedUrl": "https://books.kpl.org/iii/cas/login?service=https%3A%2F%2Fencore.kpl.org%3A443%2Fiii%2Fencore_kpl%2Fj_acegi_cas_security_check",
    "title": "Login | Kitchener Public Library",
    "frames": [
        {
            "fields": [
                {
                    "formOpid": 0,
                    "htmlId": "name",
                    "htmlName": "name",
                    "maxLength": 50,
                    "opid": 0,
                    "tabIndex": 15,
                    "type": "text",
                    "label": "First and Last Name:",
                    "labelBefore": "Login to My Account First and Last Name:"
                },
                {
                    "formOpid": 0,
                    "htmlId": "code",
                    "htmlName": "code",
                    "maxLength": 50,
                    "opid": 1,
                    "tabIndex": 20,
                    "type": "text",
                    "label": "Library card number",
                    "labelBefore": "Library card number (no spaces):"
                },
                {
                    "formOpid": 0,
                    "htmlId": "pin",
                    "htmlName": "pin",
                    "maxLength": 64,
                    "opid": 2,
                    "tabIndex": 30,
                    "type": "password",
                    "label": "Personal Identification Number (PIN):",
                    "labelBefore": "Personal Identification Number (PIN):"
                },
                {
                    "formOpid": 0,
                    "htmlName": "Log In",
                    "htmlClass": "loginSubmit",
                    "isHidden": true,
                    "opid": 3,
                    "tabIndex": 35,
                    "type": "submit"
                }
            ],
            "forms": [
                {
                    "htmlAction": "https://books.kpl.org/iii/cas/login?service=https%3A%2F%2Fencore.kpl.org%3A443%2Fiii%2Fencore_kpl%2Fj_acegi_cas_security_check",
                    "htmlId": "fm1",
                    "htmlMethod": "post",
                    "opid": 0,
                    "textContent": "Login to My Account First and Last Name: Library card number (no spaces): Personal Identification Number (PIN): Submit"
                }
            ],
            "origin": "https://books.kpl.org",
            "title": "Login | Kitchener Public Library",
            "pathName": "/iii/cas/login",
            "uuid": "7lku1h"
        }
    ]
}

1Password Version: Latest version of the firefox extension
Extension Version: Not Provided
OS Version: Not Provided