Differences between SQL Server Hierarchyid and Entity Framework HierarchyId

I am seeing different behavior for the MS SQL Server Datatype hierarchyid, and the corresponding Entity Framework 6 class System.Data.Entity.Hierarchy.HierarchyId (from the assembly EntityFramework.6.3.0\lib\net45\EntityFramework.dll).
(I was unable to find the api doc for this type, but the source code seems to be identical to Microsoft.SqlServer.Types.SqlHierarchyId)

I have a HierarchyId, e.g. childA = '/1/1.1/'. Now I want to get the next HierarchyId on the same level. So I call childA.GetAncestor(1).GetDescendant(childA,null)

Sql server returns '/1/2/', but Entity Framework returns '/1/1.2/'.

So when I insert a node into the database via Entity Framework, it gets a different ID as when using stored SQL procedures or triggers, and when I later want to search for a node by its predicted ID, the search may fail.

Is there a way to get the SQL behaviour in EF, without a database roundtrip?

Example SQL Code:

Declare @ChildA hierarchyid
select @ChildA = '/1/1.1/'
select CAST (@ChildA.GetAncestor(1).GetDescendant(@ChildA,null) as varchar) as ChildB
-- RESULT: ChildB = '/1/2/'

Example C# Code:

var childA = new System.Data.Entity.Hierarchy.HierarchyId("/1/1.1/");
var childB = childA.GetAncestor(1).GetDescendant(childA,null);
Console.WriteLine(childB);
// RESULT: ChildB = "/1/1.2/"

Copyright Notice：Content Author:「HugoRune」，Reproduced under the CC 4.0 BY-SA copyright license with a link to the original source and this disclaimer.
Link to original article：https://stackoverflow.com/questions/59302122/differences-between-sql-server-hierarchyid-and-entity-framework-hierarchyid