As the title says, the Cache of the Legion will not open after killing both Gatewatcher mini bosses in The Mechnar. Happens on both normal and heroic modes of the dungeon. After reading some prior posts, it has been like this since at least May of 2024. So almost an entire year.
you combined the keys?
Cataclysm Classic runs on the patch where the keys are removed from the game. They no longer drop. Killing Gatewatcher Gyro-Kill is supposed to trigger the Cache to unlock, but it never unlocks. You can kill every single mob in the entire dungeon and it still won’t unlock.