Code not working
 

I am using the code below and it works with numbers but not text, can anyone
help please


Sub MixerTypeFilter()

If Not UserForm7.ComboBox4.Text = "" Then
Dim MyRange, MyRange1 As Range
Lastrow = Cells(Rows.Count, "DU").End(xlUp).Row
Set MyRange = Sheets("FormulationsDatabase (2)").Range("DU1:DU" & Lastrow)
For Each c In MyRange
If Not UCase(c.Value) = UserForm7.ComboBox4.Text Then
If MyRange1 Is Nothing Then
Set MyRange1 = c.EntireRow
Else
Set MyRange1 = Union(MyRange1, c.EntireRow)
End If
End If
Next
If Not MyRange1 Is Nothing Then
MyRange1.Delete
End If
End If

End Sub