Unable to perminently name ghast

Ghast captured in minecart, in the nether, and named "Ghast" successfully. The name appears, name tag disappears from the inventory.

If I move away, die, or quit the game and return the name tag has returned to my inventory and the the ghast either appears to no longer be named or has despawned. I am able to reproduce this repeatedly by exiting the world and returning.