The author discusses an issue encountered within the Microsoft Dynamics 365 Finance & Operations (D365 FO) update 10.0.37. The update had enabled a feature titled 'Enhanced performance for source document accounting framework' by default, leading to several unexpected repercussions, including disregard for accounting structure validation and financial calendar periods, and no more validation errors. Although the feature could be temporarily disabled after posting all GL Entry, it re-enables with every software update. Microsoft acknowledged the problem as a bug, promising correction in version 10.0.39.