Found in

• Firefox 111

Affected versions

• Firefox 111

Tested platforms

• Affected platforms: Windows 10

Preconditions

• set pref extensions.formautofill.supportedCountries to IT,ES,PL,AT,BE in about:config
• set pref browser.search.region to BE in about:config
• use BE VPN
• have several credit cards saved in about:preferences#privacy

Steps to reproduce

1. Go to https://www.jbc.be/
2. Add an item to cart and proceed to checkout
3. Reach the payment page
4. Click in either the Card Number or Expiration Date field

Expected result

• Form autofill/preview/clear are applied in all the eligible fields.

Actual result

• Form autofill/preview/clear are only applied in the selected fields and the fields are not highlighted when being previewed or autofilled.

Regression range

• Not a regression because this feature is disabled by default.

Additional notes

• The issue is partially reproduceable in Google Chrome where the autofilled fields are not highlighted and the Clear form option is missing from CC number and Expiry date fields.
• Fathom Fox downloaded page: https://drive.google.com/file/d/1G382C0pDTuILhqWpm3oQsBbY-5nIiLuT/view?usp=sharing

:epopescu, if you think that's a regression, could you try to find a regression range using for example mozregression?

Fixed by bug 1916606. All the fields are now autofilled accordingly since they are all located in the same frame.
As we agreed with the engineering team and based on this comment, I will mark this as fixed and verified.
Just as a note, none of the CC fields are highlighted with the specific autofill yellow color.