I believe a variety of things can cause bud blast. When you say they 'seem' to be healthy what does that mean? Have you checked their roots/re-potted them?
When they spike & come into bud have you moved them at all? Do you have any fruit nearby? Ripening fruit gives off gases that quicken the decay of others including flowers.
If there's a cold draft nearby it could disturb the spike. Or if you under-water they can blast. Basically any changes in care or conditions can disrupt a plant especially as some are fussier than others. Think of it as the plant having to make an executive decision as to whether or not it thinks it can sustain reproduction (spikes/buds/flowers/pods). All the verbal coaching in the world
probably won't make it believe you that just cause you moved it so you could see the blooms (while it was still in bud) that it'll be okay.
That said can you give us some more background information into this situation. You said several Phals? Were they all next to each other? Were they new plants you'd just brought home (such a drastic environmental change can certainly cause bud blast though it doesn't always)? Any drafts or vents?
Bud Blast on Phals
Linear Mode
