EF Core包含查询

我正在尝试将用户实体保存到带有SQLite的EFCore中的Room实体中。保存更改后，我立即再次查询数据库以获取会议室实体中用户的更新列表。当前，它返回0个用户，如果我在运行该查询并查看数据库表后在断点处停止代码，则可以看到用户与正确的Room关联，但是我仍然得到0个结果。我很好奇我的设计是否存在问题？我需要将用户链接到房间的东西吗？

返回0个用户的代码-

public async Task<ServiceResponse<MatchRoom>> RegisterUser(AppState state)
{
    //Update the db with connection ID incase we need it later
    var update = _context.Update(state.user);
    if (update != null)
    {
        //The user object is saved here
        await _context.SaveChangesAsync();
        //Here I query a room, that the user is assigned to, but get nothing.
        var room = _context.MatchRooms.Include("Users");
}

我有以下dbcontext

public class DataContext : DbContext
{
    public DataContext(DbContextOptions<DataContext> options) : base(options)
    {
        //
    }
    
    public DbSet<User> Users { get; set; }
    public DbSet<MatchRoom> MatchRooms { get; set; }
    public DbSet<Message> Messages { get; set; }
    
    protected override void OnModelCreating(ModelBuilder modelBuilder)
    {
        modelBuilder.Entity<MatchRoom>()
            .HasMany<User>(u => u.Users);
            
        modelBuilder.Entity<MatchRoom>()
            .HasMany<Message>(m => m.Messages);
            
        modelBuilder.Entity<Message>()
            .HasOne<User>(r => r.SentBy);
    }    
}

public class MatchRoom
{
    public int MatchRoomId { get; set; }
    public string MatchRoomCode { get; set; }
    [ValidateComplexType]
    public List<User> Users { get; set; } = new List<User>();
    public User CreatedBy { get; set; }
    public List<Message> Messages { get; set; }
}

public class User
{
    public int UserId { get; set; }
    public string UserCode { get; set; }
    [Required(ErrorMessage ="You must specify a username")]
    [StringLength(20,MinimumLength=1,ErrorMessage="Please enter a username no longer than 20 characters")]
    public string Username { get; set; }
    public string ConnectionId { get; set; }
}

public class Message
{
    public int MessageId { get; set; }
    public string Text { get; set; }
    public User SentBy { get; set; }
}