Have a Brassia who's buds are drying up

[orchidilirious4]

I am concerned about my Brassia in bloom right now. It set spike about 3 weeks ago and has formed buds but now it looks like the buds are drying up and withering before being able to open. Is there something I can do or should be doing?

I have the Orchid under 2 fluorescent lights, it gets watered about once a week and misted once a week as well. The room in which it is in stays warm and has pretty good humidity. Usually about 50%. I usually try to feed with an Orchid fertilizer once a month but haven't for a while.

Any tips or suggestions would be so helpful!
Thanks!