Twice now I have bought a Paph (the last one at an orchid show) and within a week of bringing it home the bloom dropped. I was assured by the grower this time that the bloom was new, so it should have not been at the end of the cycle. I have it under lights...was that too much light?
Growers usually grow orchids under optimal conditions. Any change in those conditions while flowering usually tends to make the plant abort the flowers as they are drawing a lot of energy from the plant. It's not such an ordeal for the plant when it is not flowering or producing a new flower spike and the plant may just shortcut and produce new growth without a flower on the existing new growth. That is probably the most likely culprit.
I've had this happen too - it's so disappointing
Might be from change in conditions. I've also had it happen getting a Paph in bud, and watching it for a week or two before it just drops off
Don't be discouraged it happens to the best of us. As orchid hobbiests we have to deal with things like this from time to time. Its likey the next blooms will mean more to you the next time around
Bud blast is still the worst part of growing orchids,lol!
Most of the flowering orchids (including paphs) I've brought home have lost their blooms prematurely. I assume it's from the shock of being in a new environment. When the next bloom comes around, it should do fine.