(But there are multi-millions and millions of living entities in the vaikuṇṭha-loka, (spiritual world) they never fall down. They are called nitya-siddha.They never come here) 



Just like in this material world there are millions and millions of living entities, but they have fallen down. But there are multi-millions and millions of living entities in the vaikuṇṭha-loka, they never fall down.
They are called nitya-siddha. They never come here. So we have no information. This is only one-fourth manifestation of God's creation, and the three-fourths creation of God is there. Not creation; it is everlasting."
(Prabhupada Lecture, February 11, 1976, Mayapur)
Comments
So, very clear, jiva can leave Vaikunthas if wanton enough. Perhaps the more bold and noble venture on the thin ice and break through, take that lone journey through the darkened forest at night, I do not think that diminishes their value.