24w13a added a mechanism by which block entities (barrels, shulker boxes etc) would maintain item components of the item used to place them.

Per the blog entry:

• Does not automatically cause preserved components to be restored on drops - this requires addition of copy_components function to loot table.

And this is reflected in the loot table for shulker boxes listing only the following components to be copied across:

• "minecraft:custom_name"
• "minecraft:container"
• "minecraft:lock"
• "minecraft:container_loot"

However this behaves either incorrectly, or strangely to players, with shulker boxes when in creative mode.

In creative, there is a unique interaction when a creative player is mining a shulker box with items in it, it will create a dropped shulker box item instead of destroying it.

This unique interaction does not follow the loot table, all components are preserved.

This has lead to some confusion with players who have spawned in a "fireproof" shulker box using commands such as:

/give @s minecraft:gray_shulker_box[minecraft:item_name='{"text":"Netherite Shulker Box"}',minecraft:fire_resistant={}]

And depending on if they are in Survival or Creative when testing, have experienced differing results to what they may have seen in videos covering the snapshots. Those in survival have seen the shulker box burn, while those testing in creative falsely believe it will work as is (without the loottable modifications).