You mean the postal address autofill?

Yes, it looks like the section of the Settings page for address autofill was shortened to "Autofill" recently. The article will need to be updated.

Is the problem with stored addresses, or with the History feature ("Remember search and form history") that provides a drop-down with previously filled phrases for other kinds of fields?

• Automatically fill in your address on web forms
• Control whether Firefox automatically fills in forms / Firefox doesn't save web form entries

Oh, do you recall have to force-enable the address autofill feature because of this limitation:

Note: The address autofill feature for Firefox releases is being made available for users located in Canada, France, Germany, the U.K., Australia, India, Italy, Poland, Austria, Brazil, Japan, Spain and the U.S. This feature is being introduced to the Firefox user base through a progressive rollout. It may not yet be available in all locales.

Here is how you can do that for testing purposes:

(1) In a new tab, type or paste about:config in the address bar and press Enter/Return. Click the button accepting the risk.

More info on about:config: Configuration Editor for Firefox. The moderators would like us to remind you that changes made through this back door aren't fully supported and aren't guaranteed to continue working in the future.

(2) In the search box in the page, type or paste formautofill.addresses and pause while the list is filtered. Firefox should display numerous matching preferences. Please ignore the row at the bottom with Boolean Number String.

(3) Double-click the extensions.formautofill.addresses.supported preference to display an editing field, and change the value to on then press Enter or click the blue check mark button to save the change.

Firefox then should not to require your country to be in the extensions.formautofill.addresses.supportedCountries list. Does that work on yours?