The essence of Anguish isn't broken, it's just more complicated
There is a whole lot of new story in Destiny 2: Shadowkeep and a lot of quest steps that require you to accomplish set tasks. To complete the Shadowkeep storyline, you need to use Essences to help you and Eris Morn craft armor to defend against the nightmares.
The essence of Anguish, however, is not like the others. The essences you first meet are relatively simple "Do-this-and-it's-cleansed" type of quests. The Anguish needs you to do other tasks after the cleansing.
Full story from the WindowsCentral blog...