It has no rhyme nor reason in my experience - recent trip from CGK to BKK via KUL return in Business got me 3 of the 4 sectors credited, not the 4th - and indeed can't be bothered to attempt to claim - particularly when the last time I did this trip and claimed a segment - BAEC told me it had been credited when it hand't - gave up at that point. Great service on those MH flights though.