Error with PersistenceEnforce when using inherited entity - codefluent

Question

In my model I have set defaultPersistenceEnforce="true", because I want the database to enforce referential integrity.
However, I get an error when deleting an entity.
Here is my model:
<cf:entity name="Keyword">
<cf:property name="Id" key="true" />
<cf:property name="Value" typeName="string" />
</cf:entity>
<cf:entity name="BaseOrderline" abstract="true">
<cf:property name="Id" key="true" />
</cf:entity>
<cf:entity name="Orderline" baseTypeName="{0}.BaseOrderline">
<cf:property name="Order" typeName="{0}.Order" />
<cf:property name="Keywords" typeName="{0}.KeywordCollection" />
</cf:entity>
<cf:entity name="Order">
<cf:property name="Id" key="true" />
<cf:property name="Keywords" typeName="{0}.KeywordCollection" />
<cf:property name="Orderlines" typeName="{0}.OrderlineCollection" cascadeDelete="Before" cascadeSave="After" />
</cf:entity>
Here is my code:
Keyword keyword = new Keyword();
keyword.Save();
Order order = new Order();
order.Keywords.Add(keyword);
Orderline orderline = new Orderline();
orderline.Keywords.Add(keyword);
order.Orderlines.Add(orderline);
// Save the order and its order lines.
order.Save();
// Delete the order and its order lines.
order.Delete();
I get the following error:
The DELETE statement conflicted with the REFERENCE constraint "FK_Orl_Bas_Bas_Ore". The conflict occurred in table "dbo.Orderline_Keywords_Keyword", column 'BaseOrderline_Id'.
The DELETE statement conflicted with the REFERENCE constraint "FK_Ore_Ord_Ord_Ord". The conflict occurred in table "dbo.Orderline", column 'Orderline_Order_Id'.
Concurrency error in procedure Order_Delete
Everything goes fine if I remove orderline.Keywords.Add(keyword); from the code.
Here is the code of the stored procedure Order_Delete:
USE [PersistenceIdentity]
GO
/****** Object: StoredProcedure [dbo].[Order_Delete] Script Date: 18-7-2016 20:41:27 ******/
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
ALTER PROCEDURE [dbo].[Order_Delete]
(
#Order_Id [uniqueidentifier],
#_rowVersion [rowversion]
)
AS
SET NOCOUNT ON
DECLARE #error int, #rowcount int
DECLARE #tran bit; SELECT #tran = 0
IF ##TRANCOUNT = 0
BEGIN
SELECT #tran = 1
BEGIN TRANSACTION
END
DELETE [Order_Keywords_Keyword] FROM [Order_Keywords_Keyword]
WHERE ([Order_Keywords_Keyword].[Order_Id] = #Order_Id)
SELECT #error = ##ERROR, #rowcount = ##ROWCOUNT
DELETE [BaseOrderline] FROM [BaseOrderline]
INNER JOIN [Orderline] ON ([BaseOrderline].[BaseOrderline_Id] = [Orderline].[BaseOrderline_Id])
LEFT OUTER JOIN [Order] ON ([Orderline].[Orderline_Order_Id] = [Order].[Order_Id])
WHERE ([Order].[Order_Id] = #Order_Id)
SELECT #error = ##ERROR, #rowcount = ##ROWCOUNT
DELETE [Orderline] FROM [Orderline]
LEFT OUTER JOIN [Order] ON ([Orderline].[Orderline_Order_Id] = [Order].[Order_Id])
LEFT OUTER JOIN [Orderline] [Orderline$1] ON ([Order].[Order_Id] = [Orderline$1].[Orderline_Order_Id])
WHERE ([Order].[Order_Id] = #Order_Id)
SELECT #error = ##ERROR, #rowcount = ##ROWCOUNT
DELETE [Order] FROM [Order]
WHERE (([Order].[Order_Id] = #Order_Id) AND ([Order].[_rowVersion] = #_rowVersion))
SELECT #error = ##ERROR, #rowcount = ##ROWCOUNT
IF(#rowcount = 0)
BEGIN
IF #tran = 1 ROLLBACK TRANSACTION
RAISERROR (50001, 16, 1, 'Order_Delete')
RETURN
END
IF #tran = 1 COMMIT TRANSACTION
RETURN
As you can see the following lines are missing in this stored procedure:
DELETE [Orderline_Keywords_Keyword] FROM [Orderline_Keywords_Keyword]
WHERE ([Orderline_Keywords_Keyword].[Orderline_Id] = #Orderline_Id)