Bulbophyllum garupinum and decurviscapum

I grew garupinum for about three years in a clay pot with NZ Sphagnum in int/cool conditions. It grew fairly well, so this past year I mounted it. Most Bulbos establish better for me in a small pot with NZ Sphagnum but grow better long term when mounted…especially smaller growers from the PNG vicinity. In this case, garupinum died this past winter. One leaf after the other quickly turning yellow and falling off…reminiscent of what happens to a warm grower in a cool greenhouse . I had picked this up thinking int/cool, but everything I have read since suggests warm to hot. I did see the Orchids of New Guinea website (generally very accurate) lists it (under the Kew accepted name) as being found from 3 - 1900 meters, so would think int/cool was possible…but then they describe as a warm growing epiphyte.