The Pragmatic ability to stave off conflict for 50 turns seems broken. Used it, 6 turns later AI declares war.
Sorry to hear you are having trouble.
It would help if you could upload a savegame before the AI declared war one you, maybe even before you used the trait, to a cloud service (DropBox, Google Drive, One Drive) and post a link here, the developers can take a look at it.
Savegames are located in \Documents\My Games\GC3\Saves or \Documents\My Games\GC3Crusade\Saves
Thank you for your patience and patronage.