Thank you for adding the "From an unknown country". But we still have the problem that "All countries" is the default selection. And if people choose "all countries", it does not record the contribution in the "country" space.

Any solution will be biased I fear, but we better have any solution where "all countries" is not the default choice. Either we put "without a country" the default, or we pick up a specific country, or we pick up a randomly chosen country. I am not sure what is the easiest for you. But for WLA, the whole idea is to record country info, and since "all countries" does not allow to easily extract the country origin, all countries should not be default.

In a perfect situation, no country will be selected by default and the user HAVE to select a country before going further in the process. Then remove the "all countries" option entirely.