Garland, have you repotted it recently?
I've never grown that particular species, but try moving it to another location in your growing area--change lighting, or watering schedule, or feeding: that "little" stress is sometimes enough to spark it up again.
And, sometimes not. A hirsutissimum of mine stalled once, and never awakened. The plant put out a new growth, and the bud finally just browned
But making a little change is worth a shot.