I have not found growing Hoya sp. PNG SV 417 to have been the easiest of tasks.  There have been many stops and starts.  I put it outside last summer where it did better than it had ever done before.  It put on a long vine with several new leaves.  When I brought it inside last fall, it promptly lost all of the new growth of the summer.  Finally it started to grow again in my basement grow tent in early January where it put on a peduncle and budded up under T-5 fluorescent lighting.