The end isn't initialized when backuping a saved game which the player hadn't been to The End

When the player backup a world which The End never had been gone, the backup file has no data about The End. But after the player went to The End and tries to replace the saved file, the data of The End will not be initialized, including whether the dragon is killed, the drop items and the blocks. Importantly the advancement was replaced, which means the player may never have the advancement 'The Next Generation' if the dragon egg was picked but the saved file about advancements was replaced.

the recorded video of the bug was uploaded onto:

https://pan.baidu.com/s/1jRiBcXhlU1iqoi4gwcvXkQ?pwd=d38r 
password code : d38r