Why is the greater than operator is not working properly for some numbers?

Private Sub CommandButton2_Click()

Dim err As Integer
err = 0

If clickcount < 8 Then
    If TextBox4.Value = "" Then err = 1
    If TextBox5.Value = "" Then err = 1
    If TextBox6.Value = "" Then err = 1
    If IsNumeric(TextBox5.Value) = False Then err = 4
    If IsNumeric(TextBox6.Value) = False Then err = 4
    If TextBox6.Value > TextBox5.Value Then err = 2
    
    If err = 1 Then MsgBox "Incomplete Item Data!"
    If err = 2 Then
        MsgBox "Delivered quantity cannot be more than PO quantity!"
        TextBox5.Value = ""
        TextBox6.Value = ""
        TextBox7.Value = ""
    End If
    'MsgBox delv & " is greater than " & po
    If err = 4 Then MsgBox "Quantity value(s) incorrect!"
    If err = 0 Then
        DeliveryNote.ListBox1.ColumnCount = 5
        DeliveryNote.ListBox1.ColumnWidths = "20,120,55,50,30"
        DeliveryNote.ListBox1.AddItem
        
        ListBox1.AddItem
        ListBox1.List(clickcount - 1, 0) = clickcount
        ListBox1.List(clickcount - 1, 1) = TextBox4.Value
        ListBox1.List(clickcount - 1, 2) = TextBox5.Value
        ListBox1.List(clickcount - 1, 3) = TextBox6.Value
        ListBox1.List(clickcount - 1, 4) = TextBox5.Value - TextBox6.Value
        TextBox4.Value = ""
        TextBox5.Value = ""
        TextBox6.Value = ""
        TextBox7.Value = ""
        
        clickcount = clickcount + 1
    End If
Else

MsgBox "Sorry! You cannot add more than 7 items in single delivery note!" & vbNewLine & "Create another delivery note for remaining items."

End If

End Sub

Error

Accepted Values

I have attached the values resulting in error as well as the values that got processed without error. I want the the condition to always work and not give these kind of errors.

Maybe try and cast your text to a number before performing the comparison. Right now, it's probably just comparing strings.

Try this instead (untested) ...

If CDbl(TextBox6.Value) > CDbl(TextBox5.Value) Then err = 2