If you go to the QF Qpoints and QF SC earn calculator, ADL - HKG in premY indeed earns 50 QF SC, and MEL - HKG or vv, in premY earns 30 QF SC.
Not wrong QF SC, as in the title of the thread, more so its the appropriate QF SC earn for a partner.
As Moa999 mentioned in the light blue linkage.