Interesting to learn other people encounter the same problem as I do. The Wololo achievement is bugged by me as well.
As far as I’m concerned:
"
most achievements that require a certain amount of something (eg collect 100 relics, get 100 conversions by a missionary, etc.) are bugged by me. They get to a certain number and then won’t progress any further.
It’s odd I’ve for instance never got the farms achievement, even though the hussar spam is my favorite strat in the game… 11
"
(see New obtained medals disappear since last patch - #2 by AoE2and3fan)