Silmarillion
Chieftain
Ever since Hungary released, their Achievement (As Hungary, have Christianity as your dominant religion and defeat a unit whose Civilization's dominant religion is not Christianity) has been the second-most-impossible thing to get for my achievement-addicted self (the most impossible being An Engineer's Dream). 
After many games played as them, in which it was either impossible to get a religion at all, or none of the Christian Religions were left (achievement guides claim that either Catholicism, Protestantism or Eastern Orthodoxy will work for the Achievement), I finally thought that today, I had all the pieces together!
As you can see from my Save, I got Eastern Orthodoxy (the other two were already gone, close!). It should be my Dominant Religion, since I only have the one city. I have been slaughtering Japanese Units for several turns now, who are definitely units of Buddhism (all the Japanese cities are Buddhist). But still, no Achievement
Over a year ago, I already had a Hungary Game once where I also thought I had all the pieces, and it didn't work then, either... at the time, I shrugged and thought I must have done something wrong, but now I'm convinced that the Achievement is simply broken, like so many other things in this game.
If I'm overlooking something completely obvious, please let me know. I admit that I still have no idea how religions/believers/dominance really work, even after over 2000 hours played.
Is it only one of the three that actually counts as Christianity for the Achievement? Do none of them, due to broken coding?(Would a Custom Religion named "Christianity" work then!?!) Do I need more than one city? Does it secretly work only for Religious Combat?
Thank you for reading.

After many games played as them, in which it was either impossible to get a religion at all, or none of the Christian Religions were left (achievement guides claim that either Catholicism, Protestantism or Eastern Orthodoxy will work for the Achievement), I finally thought that today, I had all the pieces together!

As you can see from my Save, I got Eastern Orthodoxy (the other two were already gone, close!). It should be my Dominant Religion, since I only have the one city. I have been slaughtering Japanese Units for several turns now, who are definitely units of Buddhism (all the Japanese cities are Buddhist). But still, no Achievement

Over a year ago, I already had a Hungary Game once where I also thought I had all the pieces, and it didn't work then, either... at the time, I shrugged and thought I must have done something wrong, but now I'm convinced that the Achievement is simply broken, like so many other things in this game.
If I'm overlooking something completely obvious, please let me know. I admit that I still have no idea how religions/believers/dominance really work, even after over 2000 hours played.
Is it only one of the three that actually counts as Christianity for the Achievement? Do none of them, due to broken coding?(Would a Custom Religion named "Christianity" work then!?!) Do I need more than one city? Does it secretly work only for Religious Combat?
Thank you for reading.