It could be due to Ramadan but that begs the question why put it on sale if you were going to reduce it a few weeks later and thus upsetting pax who would have purchased tickets on flights for those days. Another question is why reduce it from the beginning of May when Ramadan actually runs from 16th May to 15th June. It is all very intriguing but then so is dropping it to 5x weekly for the Southern Hemisphere Summer!