The bug

The name nbt tag doesn't produce an error when it is changed to a not formatted string. And the name will not be shown.

How to reproduce

1. Run:

   /give @p minecraft:diamond_ore{display:{Name:"This Will not appear."}}
   

2. Throw the item on the ground
3. Run:

   /data get entity @e[type=item,limit=1,sort=nearest]
   

   → You will see the tag is set but not displayed

What should happen

The game should show an error, much like book pages do when invalid JSON is used as a value (producing the message "invalid book tag").