When is a traveler prohibited from breaking their fast? Please mention the reason.

It is permissible for a traveler to break their fast in Ramadan if certain conditions are met: the journey must be long enough to permit shortening prayers (approximately 80 km according to the majority of scholars), and it must be a permissible journey. It is not permissible for them to break their fast if the journey does not reach the distance for shortening prayers, or if it is a journey undertaken for disobedience (a sinful journey), or if they traveled specifically to break their fast. Furthermore, it is forbidden for them to break their fast before leaving the inhabited area of their city. Scholars have differed regarding journeys undertaken for disobedience; some have disallowed the concession for such journeys, while others have permitted it.