Connect4 with logic fail -TizzyT

'TASK: Find the problem in the connect4 program and fix it.
'Some instances of connect4 isn't detected as such.

Module Module1
    '''' Empty = 0, Player1 = 1, Player2 = 2
    Private Board(,) As Byte = {{0, 0, 0, 0, 0, 0}, _
                                {0, 0, 0, 0, 0, 0}, _
                                {0, 0, 0, 0, 0, 0}, _
                                {0, 0, 0, 0, 0, 0}, _
                                {0, 0, 0, 0, 0, 0}, _
                                {0, 0, 0, 0, 0, 0}, _
                                {0, 0, 0, 0, 0, 0}}

    '' If False = PlayerOnes Turn, True = PlayerTwos Turn
    Private Player2sTurn As Boolean = False

    Private Function Win(ByVal Column As Byte, ByVal Row As Byte) As Boolean
        Dim CheckingFor As Byte = 0
        If Player2sTurn Then CheckingFor = 2 Else CheckingFor = 1
        If Column > 2 Then
            For i = 1 To 3
                ' Checks Left
                If Board(Column - i, Row) <> CheckingFor Then Exit For
                If i = 3 Then Return True
            Next
        End If
        If Column < 4 Then
            For i = 1 To 3
                ' Checks Right
                If Board(Column + i, Row) <> CheckingFor Then Exit For
                If i = 3 Then Return True
            Next
        End If
        If Row > 2 Then
            For i = 1 To 3
                ' Checks Down
                If Board(Column, Row - i) <> CheckingFor Then Exit For
                If i = 3 Then Return True
            Next
        End If
        If Column > 2 AndAlso Row < 4 Then
            For i = 1 To 3
                'Check Up Left
                If Board(Column - i, Row + i) <> CheckingFor Then Exit For
                If i = 3 Then Return True
            Next
        End If
        If Column < 4 AndAlso Row < 4 Then
            For i = 1 To 3
                'Check Up Right
                If Board(Column + i, Row + i) <> CheckingFor Then Exit For
                If i = 3 Then Return True
            Next
        End If
        If Column > 2 AndAlso Row > 2 Then
            For i = 1 To 3
                'Check Down Left
                If Board(Column - i, Row - i) <> CheckingFor Then Exit For
                If i = 3 Then Return True
            Next
        End If
        If Column < 4 AndAlso Row > 2 Then
            For i = 1 To 3
                'Check Down Right
                If Board(Column + i, Row - i) <> CheckingFor Then Exit For
                If i = 3 Then Return True
            Next
        End If
        Return False
    End Function

    Private Function PlaceChip(ByVal Column As Byte) As Byte
        For i = 0 To 5
            If Board(Column, i) = 0 Then
                If Player2sTurn Then Board(Column, i) = 2 Else Board(Column, i) = 1
                Return i
            End If
        Next
        Return 0
    End Function

    Private Function IsColumnFull(ByVal Column As Byte) As Boolean
        For i = 5 To 5
            If Board(Column, i) = 0 Then Return False
        Next
        Return True
    End Function

    Sub Main()
        While True
            If Player2sTurn Then
                '' Player Twos Logic
                ''''''''''''' Make sure user picks a valif column
                Console.WriteLine("2 - Pick a column (1-7)")
                Dim Column As Byte = Console.ReadLine
                While Column < 1 OrElse Column > 7
                    Console.WriteLine("2 - Invalid number, Pick a column (1-7)")
                    Column = Console.ReadLine
                End While
                Column -= 1
                ''''''''''''' Make sure the column the user picks isnt full
                If IsColumnFull(Column) Then
                    Console.WriteLine("Column full, Pick another column")
                    Continue While
                Else
                    Dim Row As Byte = PlaceChip(Column)
                    PrintBoard()
                    ''''''''''''' Checks to see if player won
                    If Win(Column, Row) Then
                        Console.WriteLine("PLAYER 2 WON!")
                    Else
                        Player2sTurn = False
                    End If
                End If
            Else
                '' Player Ones Logic
                ''''''''''''' Make sure user picks a valif column
                Console.WriteLine("1 - Pick a column (1-7)")
                Dim Column As Byte = Console.ReadLine
                While Column < 1 OrElse Column > 7
                    Console.WriteLine("1 - Invalid number, Pick a column (1-7)")
                    Column = Console.ReadLine
                End While
                Column -= 1
                ''''''''''''' Make sure the column the user picks isnt full
                If IsColumnFull(Column) Then
                    Console.WriteLine("Column full, Pick another column")
                    Continue While
                Else
                    Dim Row As Byte = PlaceChip(Column)
                    PrintBoard()
                    ''''''''''''' Checks to see if player won
                    If Win(Column, Row) Then
                        Console.WriteLine("PLAYER 1 WON!")
                    Else
                        Player2sTurn = True
                    End If
                End If
            End If
        End While
    End Sub

    Private Sub PrintBoard()
        Console.Clear()
        For y = 5 To 0 Step -1
            For x = 0 To 6
                Console.Write(Board(x, y) & " ")
            Next
            Console.Write(vbCrLf)
        Next
    End Sub
End Module