I am performing a read operation from the XLS file and doing the insert if the data is not present in the table.

DB Operation:

foreach (var transaction in transactions)
{
    if (!_dbContext.Transactions.Any(t =>
        t.TransactionDate.Date == transaction.TransactionDate.Date &&
        t.ValueDate.Date == transaction.ValueDate.Date &&
        t.Balance == transaction.Balance &&
        t.ChequeNumber!.Trim() == transaction.ChequeNumber!.Trim() &&
        t.TransactionRemarks.Trim() == transaction.TransactionRemarks.Trim() &&
        t.WithdrawalAmount == transaction.WithdrawalAmount &&
        t.DepositAmount == transaction.DepositAmount))
    {
        _dbContext.Transactions.Add(transaction);
    }
}
await _dbContext.SaveChangesAsync();

DBContext:

protected override void OnModelCreating(ModelBuilder modelBuilder)
{
    base.OnModelCreating(modelBuilder);

    modelBuilder.Entity<Transaction>()
    .HasKey(t => new {
        t.TransactionDate,
        t.ValueDate,
        t.Balance,
        t.ChequeNumber,
        t.TransactionRemarks,
        t.WithdrawalAmount,
        t.DepositAmount
    });
}

The XLS file has some duplicate data and to avoid the duplicate insert I already have an if statement that will not add data to the context. However, the code is not working the way it should and I am getting the below error:

The instance of entity type 'Transaction' cannot be tracked because another instance with the same key value for {'TransactionDate', 'ValueDate', 'Balance', 'ChequeNumber', 'TransactionRemarks', 'WithdrawalAmount', 'DepositAmount'} is already being tracked.

Transaction Model:

public class Transaction
{
    [NotMapped]
    public int SNo { get; set; }
    [DatabaseGenerated(DatabaseGeneratedOption.Identity)]
    public int ID { get; set; }
    public DateTime ValueDate { get; set; }
    public DateTime TransactionDate { get; set; }
    public string? ChequeNumber { get; set; }
    public string TransactionRemarks { get; set; } = string.Empty;
    public decimal? WithdrawalAmount { get; set; }
    public decimal? DepositAmount { get; set; }
    public decimal Balance { get; set; }
}

What am I doing wrong?