Loremaster woes

I’m working on this achievement and it’s going great, only 8 more zones to go. Except that there’s a small detail that troubles me. I already have Loremaster of Eastern Kingdoms, which is no surprise since I’ve been playing mostly Alliance characters since 2009 I think. But one thing is off : I’m missing some zone completion achievements. In the meta they appear completed, but when I look at the individual achievements, some are still greyed out. Can anyone put some light into this? Maybe there was a patch around 2010 that messed with this stuff?

Thank you for reading.

not a patch, but an expansion.
Cataclysm changed Loremaster from complete a certain amount of quests, to complete specific storylines in each zone.

Horde and alliance don’t share all zones for questing, so some zones will show as incomplete if you look at the achievement on a character of the opposing faction.

I remember that change. I think I was halfway done with Kalimdor, and it reset mostly everything to 0 because I had not hit the magic number. But the opposite happened too, where I hit the number but now the quests are lacking. Still got the achieve on the meta, but the zone completion was replaced. Oh well, maybe I’ll do them again one day. Thanks Nobully.