Yes, I do have Paph stonei, as a matter of fact I have 2 different clones. Like other large multilforal Paph species, it requires very bright light to bloom. Surprising, one of my stoneis is an extremely slow grower and it seems to like a little less light than the other. It sounds like you may have the same clone. The other clone is totally the opposite, it is more robust fast growing, loves very very bright light, already a multigrowth plant and could spike any day.
If your stonei has bleached out leaves, it may be getting too much bright light. These large multifloral Paph species can be very picky sometimes.
Hope this helps!