I read through this FAQ and last years as well and haven't found my answer (or maybe I'm just missing it).
I am trying to make an Avios booking on MH. MH has revenue flights (I didn't search for award space on a 3rd party tool) but I have checked BA.com for a November 2018 itinerary and nothing is available (It doesn't show any results). I've tried various time points on different days of the week for next month, and the months following but no results. Is there a trick to booking an MH flight? This is for economy KUL-LGK.