Shulker boxes in saved hotbars inconsistently update to item components

Shulker boxes full of items with nbt data, saved to a hotbar before item components, do not always update automatically to use the new system, leaving empty shulker boxes

Most often due to items inside the shulker box having NBT values that can no longer be parsed correctly, deleting the entire inventory of the shulker box rather than just the invalid component

Has happened in at least one case with entirely valid items, cause still unknown