The app does not allow edits to the pre-existing card view contents

public JsonResult EditUserJ(int Id)    //For getting details of the selected User  
    {  
       //EditUserJ is set to 200 (ok) on devtool however the response is null as the id is set to the wrong index
        try  
        {
            var User = _context.ListingDTO_DBTable.Find(Id);  //somehow it is set to Id = 0 !! wrong. 
            if (User != null)  
            {  
                Console.WriteLine($"Got it");
                return Json(User);  
            } 
            
            return Json(null);  //My MariaDB Datatable has no entry with the Id 0, so it simply returns null
            
        }  
        catch (Exception ex)  
        {  
            return null;  
        }  
    }