Just finished an Immortal domination game that had Egypt in it. I took 4 or 5 of their cities (including Thebes) in the Modern Era but none of them had burial tombs. Since Egypt had built around 80% of the wonders in that game and were no.1 in almost every demographic (until they declared war on me

) I find it hard to believe that the achievement is working. However, 0.1% of people have unlocked it.
My conclusion is that either (i) Egypt rarely build their UB, or (ii) the achievement is broken but some people have managed to find a way round it.
Has anyone on here unlocked it?
(Just a thought, but what about if you play as Egypt, build a burial tomb in a city, and then allow that city to be captured by someone else. Might be worth a try?)