Asp Net core web API. EF Core не отслеживает изменения Entity

public class User
{
    [Key]
     public int Id { get; set; }
 
    [Required]
    [StringLength(50, MinimumLength = 5)]
    public string Nickname { get; set; }
 
    [EmailAddress]
    public string Email { get; set; }
 
    [Phone]
    public string PhoneNumber { get; set; }
 
    [Required]
    [StringLength(50, MinimumLength = 5)]
    public string Password { get; set; }
 
    public int UserTypeId { get; set; } 
 
    public virtual UserType UserType { get; set; }
} 
 
public class UserType
{
    [Key]
    public int Id { get; set; }
 
    [Required]
    [StringLength(50, MinimumLength = 5)]
    public string Name { get; set; }
}

public class UserCreateDto
{
    [Required(AllowEmptyStrings = false, ErrorMessage = "Nickname not specified")]
    [StringLength(50, MinimumLength = 5)]
    public string Nickname { get; set; }
 
    [EmailAddress]
    public string Email { get; set; }
 
    [Phone]
    public string PhoneNumber { get; set; }
 
    [Required(AllowEmptyStrings = false, ErrorMessage = "Password not specified")]
    [StringLength(50, MinimumLength = 5)]
    public string Password { get; set; }
 
    [Required(AllowEmptyStrings = false)]
    [Compare("Password", ErrorMessage = "Passwords don't match")]
    public string PasswordConfirm { get; set; }
}
 
public class UserTypeCreateDto
{
    [Required(AllowEmptyStrings = false, ErrorMessage = "User's type not specified")]
    [StringLength(50, MinimumLength = 3)]
    public string Name { get; set; }
}

public class UserReadDto
{
    public int Id { get; set; }
    public string Nickname { get; set; }
    public string Email { get; set; }
    public string PhoneNumber { get; set; }
    public UserTypeReadDto UserType { get; set; }
}
 
public class UserTypeReadDto
{
    public int Id { get; set; }
    public string Name { get; set; }
}

public async Task<User> AddAsync(User user)
{
    var context = dbContextFactory.Create(typeof(UserRepository));
 
    var userTypeId = await context.UserTypes
                                  .Where(x => x.Name == "Client")
                                  .Select(x => x.Id)
                                  .FirstOrDefaultAsync();
    if (userTypeId == 0)
    {
        UserType userType = new UserType
        {
            Name = "Client"
        };
 
        await context.UserTypes.AddAsync(userType);
        await context.SaveChangesAsync();
 
        userTypeId = userType.Id;
    }
 
    User newUser = new User
    {
        Nickname = user.Nickname,
        Email = user.Email,
        PhoneNumber = user.PhoneNumber,
        Password = user.Password,
        UserTypeId = userTypeId
    };
 
    await context.Users.AddAsync(newUser);
    await context.SaveChangesAsync();
 
    return newUser;
}

[HttpPost("")]
public async Task<IActionResult> CreateUserAsync(UserCreateDto userDto)
{
    if (userDto == null || !ModelState.IsValid)
    {
        return BadRequest(ModelState);
    }
 
    var user = mapper.Map<User>(userDto);
 
    //after saving to the database(context.SaveChangesAsync()), the user model is not updated.
    //I was unable to fix this.So I do the following:
    
    var userResult = await userRepository.AddAsync(user); // get user with Id from database.
 
    userResult = await userRepository.GetByIdAsync(userResult.Id); // get user with userType from 
    database.
 
    var userReadDto = mapper.Map<UserReadDto>(userResult);
 
    return CreatedAtAction(nameof(GetUserByIdAsync), new { id = userReadDto.Id }, userReadDto);
}