The author of Norland published a detailed post on Reddit explaining why there are so many bugs in the game.
Norland consists of many interconnected systems — war, economy, religion, and others. They are divided into low- and high-level systems. In the former, the elements are simple, while in the latter, even the basic components are extremely complex. Most of Norland's systems are high-level, which creates a lot of exceptions and unique connections where bugs arise in unpredictable places.
Developers prefer innovation to classic solutions. Their approach makes the game original but increases the complexity of debugging. New systems are developed to ~80%, which allows them to work but does not make them perfect. According to the author, from the three elements "high complexity", "innovation", "game without errors" you can choose only two, and the studio chose the first two.
The latest patch 41 added public conspiracies, a developer mode, and minor changes: the "loyalty base" technology was removed, and the chances of buildings catching fire over time were increased.