The "untracked" metadata field turns off tracking of soft object references so they will not appear in the content browser or modify things like cooking rules. It works fine on individual references, but is currently broken on arrays/maps/etc.
The fix is simple, the code that reads the metadata needs to call GetOwnerProperty before checking metadata. This is probably also broken for other types of metadata reads.
Untracked should prevent the soft object references from being listed, so if you see the object reference this is still broken
There's no existing public thread on this issue, so head over to Questions & Answers just mention UE-119853 in the post.