Despite Name Tags allowing Creakings to not despawn during day time, they still despawn after reloading a World. This happened to me in a Survival World where my named Creaking disappeared after i loaded back the World.
The video below shows proof of this Bug.
Linked issues
Attachments
Comments 2
This issue is being tracked at MCPE-190845.
Also something i forgot to mention; when night time arrives, the Creaking Heart spawns in another Creaking which does not have a Name Tag, meaning that original Creaking alongside the Name Tag both get erased.