I too have a Paph not blooming problem. They are all far from the sunlight the catts oncidiums and some of my other plants get but the mottled leaf ones are not doing so well. New growth but old leaves decaying. Do the roots need to be above the medium or buried ?
Far from sunlight could be an issue depending on how shady it is. Too shady, they won't like it.
Old leaves may stay around for a long time (a couple of years or more) but some bottom leaves may fade much sooner depending on the plant and its condition.
Roots need to be buried. They will dig in on their own. Under high humidity condition, some roots may stay above the the medium.