Map Editor - Exclude From Countries Bugged

Expected Behavior:
When units are set to be excluded from certain countries they will in fact be excluded from those countries.

Actual Behavior:
When editing a map of mine and adding in new unit types, I ran into some issue where setting units to be excluded from specific countries made them become only availible in those countries.

Steps To Reproduce The Behavior:
I've gone back into the editor and tried, actually, to NOT reproduce the behavior. But it seems to be persistent. Additionally, units from the same map that were properly excluded from specific countries are now - in game - availible to all countries including the ones they're listed as excluded from.

For example, in my 1800's scenario, the French are supposed to be able to produce an advanced form of Cavalry, and thus the default Cavalry unit is excluded from the French 'countries.' This has worked just fine in my game for years. But after today, when trying to exclude some new units from specific countries, the Cavalry (which were not even touched) thereafter became availible to French 'countries' as well despite being excluded from them on the unit's info sheet. And I can't seem to be able to undo that.

Information:
Map Editor through the browser.

No response to the bug yet, but it's expanded. I tried fixing the cavalry (using a test copy map so I don't more break my game irreversibly) by creating a new unit altogether with the same parameters. Excluded from France - and yet, it's availible in france despite being clearly listed when you click on the unit as excluded from those countries

It would seem Exclude From Countries just doesn't work at all at this point.

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Edit: After more tweaking (unselecting and reselecting the excluded countries) I seem to have fixed my game and they are properly excluded. Though when I open the map editor, it still lists them as availible if I select a city in that country.

I'm listing this here in case someone has a similar problem to me in the future - I don't know why it worked, but it seems to be possible to at least functionally fix this bug by undoing and re-doing it enough times.