Affected Versions:

Nightly 98.a1, Beta 97 and Release 96

Tested on:

MacOS 11
Windows 10

Preconditions:

browser.search.region CA
extensions.formautofill.addresses.enabled - true
extensions.formautofill.supportedCountries US,CA
download latest Firefox Nightly with region locale
have a complete address already saved in about:preferences#privacy

Steps to reproduce:

1. Reach the address form on bestbyt.ca
2. Using the autofill feature, select 1 saved address entry.
3. Click in the address/city/postal code fields.

Expected Results:

1. All the fields should be successfully autofilled.
2. The address autofill dropdown should be displayed for all fields.
3. The address autofill eligible fields should be previewed as filled in upon hovering over a CC entry from the dropdown.

Actual Results:

1. The address/city/postal code/province fields are not autofilled.
2. The address autofill dropdown is not displayed for address/city/postal code fields.
3. The address autofill eligible fields are not previewed as filled in upon hovering over a CC entry from the dropdown.

Notes:

Reproducible on Chrome: No, the address dropdown trigger, the fields preview and autofill functionality are working as expected for all the fields on Chrome.
Please let me know if separate bugs are needed for the issues above.

Cannot reproduce the issues described above anymore, using Beta 103.0b2 and the latest Nightly build 104.0a1. Tested on Windows 10 and macOS 12. I will file a new issue for the autofill-specific yellow highlight that is missing.