A Test Project to Reproduce an issue with Nhibernate using custom types

Repro create a local Database named test in MSSQLSERVER

    CREATE TABLE Product (
        Id INT IDENTITY(1,1) PRIMARY KEY,
        Name NVARCHAR(MAX),
        ValidFrom DATE NOT NULL DEFAULT CAST(GETDATE() AS DATE),
        ValidUntil DATE
    );
    
    INSERT INTO Product (Name, ValidUntil)
    VALUES 
    ('Product A', '2025-12-31'),
    ('Product B', NULL),
    ('Product C', '2026-06-30'),
    ('Product D', NULL),
    ('Product E', '2025-09-15'),
    ('Product F', NULL),
    ('Product G', '2027-01-01'),
    ('Product H', NULL),
    ('Product I', '2025-08-01'),
    ('Product J', NULL);

Create a products table and insert some products using the script above. Change your connectionstring in the Program.cs file to use your credentials/login method. Then call from the Swagger UI