diff snap usage in child pipeline

I use a diff snap to process records coming from a REST API call with records stored in a database.  Records from the REST call are "New";  records from the database are "Original".   

When the diff is in the parent pipeline everything works as expected. 

When the diff is in a child pipeline and called with Pipeline Execute it does not.  During the inital run there are no original records and all "New" records should be inserted; however, only one record is inserted and the rest are deleted.  I have tried reusing existing connections, but that results in all records being treated as "New" each time the parent pipeline runs.  Using a Gate or Group by N snap within the child pipeline causes a SQL error.