将nvarchar值“ EnumValue”转换为数据类型int时，Entity Framework Core 3.1枚举转换失败

我正在使用Entity Framework Core 3.1并尝试对我的localdb中实体中的enum属性进行简单查询，但不断出现此错误：

将nvarchar值“ Accountant”转换为数据类型int时，枚举转换失败

实体：

public class DemoEntity
{
    [Key]
    public int Id { get; set; }
    public string FirstName { get; set; }
    public string LastName { get; set; }
    public Position Position { get; set; }
}

枚举-位置：

public enum Position
{
    [Display(Name = "Accountant")]
    Accountant,
    [Display(Name = "Chief Executive Officer (CEO)")]
    ChiefExecutiveOfficer,
    [Display(Name = "Integration Specialist")]
    IntegrationSpecialist,
    [Display(Name = "Junior Technical Author")]
    JuniorTechnicalAuthor,
    [Display(Name = "Pre Sales Support")]
    PreSalesSupport,
    [Display(Name = "Sales Assistant")]
    SalesAssistant,
    [Display(Name = "Senior Javascript Developer")]
    SeniorJavascriptDeveloper,
    [Display(Name = "Software Engineer")]
    SoftwareEngineer
}

DbContext：

public class DemoDbContext : DbContext
{
    public DemoDbContext(DbContextOptions options)
        : base(options) { }

    public DbSet<DemoEntity> Demos { get; set; }

    protected override void OnModelCreating(ModelBuilder modelBuilder)
    {
        //var converter = new ValueConverter<Position, string>(
        //                    v => v.ToString(),
        //                    v => (Position)Enum.Parse(typeof(Position), v));

        //var converter = new EnumToStringConverter<Position>();

        modelBuilder
            .Entity<DemoEntity>()
            .Property(e => e.Position);
            //.HasColumnType("nvarchar(max)")
            //.HasConversion<string>();
            //.HasConversion(converter);
    }
}

我尝试添加价值转换：

1. .HasConversion<string>() -没用
2. .HasConversion(converter) -没用

当我如下查询表时，出现转换错误

try
{
    var test = await query.Where(x => x.Position.Equals(Position.Accountant)).ToListAsync();
}
catch (System.Exception e)
{
    //throw;
}

该Position类型是NVARCHAR(MAX)在我的数据库。

我缺少任何简单的东西吗？无法找出我要去哪里。请协助。