RetrieveDuplicatesRequest TotalRecordCount

When retrieving duplicates for an entity the total record count is not returning the expected result.  Is this a bug or am I using this incorrectly?

Here is the relevant code:

Lead lead = entity.ToEntity<Lead>();

RetrieveDuplicatesResponse response = (RetrieveDuplicatesResponse)service.Execute(
	new RetrieveDuplicatesRequest
	{
		BusinessEntity = lead,
		MatchingEntityName = Lead.EntityLogicalName,
		PagingInfo = new PagingInfo { PageNumber = 1, Count = 50, ReturnTotalRecordCount = true }
	});

int duplicateLeads = response.DuplicateCollection.TotalRecordCount;
int duplicateCollectionCount = response.DuplicateCollection.Entities.Count;

In this case I am getting back that the given entity has one duplicate record, which is expected.  But duplicateLeads is -1; the parameter response.DuplicateCollection.TotalRecordCount returns -1 even though I set ReturnTotalRecordCount to true.  But it definitely should not be -1 because response.DuplicateCollection.Entities.Count, the count of how many duplicates were returned in this page, is 1.

This is being executed against Crm 2016 online.  Thanks for any help!