After I end my turn in this saved game, Eleanor will kill my martyr-promoted apostle with an apostle. I'm playing Mvemba Nzinga, and my palace already has 5 relics, but I also have a bank with two slots which can hold anything, including relics. (I paid dearly to get the Great Merchant Giovanni de' Medici for exactly this purpose.) I don't get a relic from the martyr dying to theological combat UNLESS I move a relic from the palace to this bank. (You can try it both ways from this saved game.) So the bug is that the game doesn't recognize this bank as a location for relics from martyrdom.