Testing on Windows 11, version 25.02. Anki has always behaved this way, as far as I remember.

In the Card Browser, you can rename each flag using the right-click context menu. However, once you rename a flag, there seems to be no way to restore the default name. You can manually enter a name identical to the original, but this won’t use Anki’s default string, meaning it won’t update if there are changes or if you switch the interface language.

A couple of ideas:

1. If a custom name is being used, add a "Restore Original Name" option to the right-click context menu.
2. Revert to the original string if the user clicks "Rename", deletes the custom name, and then confirms the change.