One of the achievements for the Shadowlands command table is named “Adventures: Into the Breach” and requires that your followers beat the series of “Maw” missions that reward Soul Ash (Each mission starts out with “Maw:” in its title). The missions are:
Breach the Planes
Ghelak’s Revenge
Coalescing Stygia
Topple the Giants
Dark Skies, Darker Prospects
Dravok’s Plot
Grandiose Designs
Cutting the Threads
Shades of Despair
Krala, Wings of Woe
Initially, these missions come on a weekly basis. You beat the first one, then the next week the next one in the chain is offered. But after around the fourth one, the game stops offering the next missions in the chain.
A few people have had it continue on, most have not. It’s been like this for several months now, where a lot of people are “stuck” at it not offering the next one in the chain. Instead, the game re-offers missions named after the first four, but without the word “Maw” in the mission title.
There’s a lot of comments about the issue on the wowhead page: https://www.wowhead.com/achievement=14844/adventures-into-the-breach#comments
This seems to be a clear bug that should not be brushed off as “it’s just RNG.” It makes no sense to have this chain start out as a “week to week” succession, then after one month have the thing just come to what is practically a dead halt for some 1/1000 chance at the thing continuing on in a way no player can figure out.
Because of this mission chain being bugged, it means the achievement is effectively broken as well.