The big problem me and other people found with CX, is that for some reasons almost all direct availability disappeared from the last big program change, leaving almost only married segments.
E.g. searching BRU-HKG for 8th Dec. 2019 returns no availability with CX, but if you search BRU-HKG-KUL the same day then you find it, and f you call BA to book only the BRU-HKG leg, they can't.
When the 26th Dec 2019 becomes bookable, try also to search fro SIN, KUL, BKK etc.