Many people seem to have difficulty flowering Hoya archboldiana and Hoya macgillivrayii.  Both of these plants are in the same complex and their care is identical.  I grow them in high humidity grow tents that must be large enough to accommodate their large size.  They don’t require a huge amount of light; I flowered this one under a compact fluorescent bulb of 125 watts; it also had some peripheral LED light.  I will finish up this discussion tomorrow.