What is the ruling on the اختلاف (disagreement/divergence) within a single mosque congregation regarding the fasting of Ramadan due to the imams, and is the fast of one who fasts with the rest of the Arab countries valid?

Fatwa no. 102580 clarified the methods by which the beginning of Ramadan is established. If the crescent moon was sought in the aforementioned country but not sighted, scholars have differed on whether to adopt the sighting of other countries, and there is latitude in this matter. As for relying on astronomical calculations, it is not considered valid for determining the beginning and end of the month. What is obligatory is to act upon the sighting of the nearest countries whose people sight the crescent moon.