Game concept · By God Alone
Instability Chapter
The game also links it as Instability.
From the game's encyclopedia
An Instability Chapter of The Christian Church is one where obedience runs thin:
Rulers may be more easily swayed to a different Rite, excommunications may happen more frequently, and Gold may be spent for one's own benefit.
Fragile Unity and Reform are Instability Chapters.
The game's text for patch 1.20.1.2. Words in blue are entries of the encyclopedia: hover one to read it, as in the game.
Instability Chapter is an entry of Crusader Kings III's in-game encyclopedia (By God Alone). The game explains it: "An Instability Chapter of The Christian Church is one where obedience runs thin:" It is part of Chapter Type. The game also links it as Instability. Patch 1.20.1.2, from game/common/game_concepts/pam_game_concepts.txt and game/localization/english/game_concepts_l_english.yml.
Source: game/common/game_concepts/pam_game_concepts.txt, game/localization/english/game_concepts_l_english.yml and the English localisation, Crusader Kings III 1.20.1.2.