Pleurothallis grobyi - grows like a weed, but won't flower

[calonyction]

Howdy. I have a Pleuro. grobyi, which I have read everywhere seems to be easy peasy to grow and flower.

Mine grows like a weed. It's covering its mount and many leaves are strong and thick and healthy. I've had the darling for a couple years now.

I have tried high light, low light, fertilizer, no fertilizer, little fertilizer, etc. I water it little because it's in a tank in which the humidity is very high (and it has lots of winding aerial roots) -- and it rarely, if ever, dries out. It gets the occasional misting these days; I used to dunk it in water. It doesn't seem to care - it grows the same anyway...like a weed.

What am I doing wrong? I adore this plant. Would love to see it begin flowering. Any tips would be greatly appreciated.