Optimize World: Chest ordering random / items missing

When using the Optimize World option to convert my 1.12 world to 1.13, chest items are not in their original inventory slots.  This appears randomly and doesn't affect every chest.  I have noticed this in chunks that would have been initialized in numerous game versions.

The greater issue: some items are disappearing entirely from chests.  I have only noticed missing items in a room of chests near spawn (chunk would have been created in 1.7.10).  Attached are 1.12/1.13 images showing the behavior.