Ponerorchis graminifolia bud blast

[Nlamr]

Curious if anyone would have thoughts or suggestions... My graminifolia grows beautifully, and this year had twice as many buds as last year but both last year and this year the buds get almost ready to burst, then stall and never open. They don't suddenly all drop at once, it is gradual. Because this is the second year in a row that this has happened I am curious if I am missing something in their culture rather than external factors. They are potted in kanuma, and I keep the media moist, distilled water only. I do use MSU fertilizer but it is very minimal, I have actually only fertilized them once all summer at 1/4 the recommended dosage and that was previous to the spikes forming. They have been kept outside since Spring (I keep them in my fridge over winter because they will not survive my Winters). They are on an East facing, covered porch and the temperatures have stuck around 60-70° at night and 70-85° during the day for the last 2 months. They essentially get the same care as my Habineria radiatas and those bloomed beautifully last year and I have no reason to believe they won't this year as well based on the health of the plants. Any thoughts are greatly appreciated!