Hoya piestolepsis Won’t Flower – Why?

I may have to move Hoya piestolepsis into the Hall of Shame shortly if I can’t figure out how to bloom it. The plant is huge with numerous peduncles, but it refuses to bud up. I suspect that there is a blooming trigger that I am missing such as increasing or decreasing day length that is the issue. I will have to start trying different things.