When I put the code below in a UserForm (VBA Editor) it works as it should but when I use an ActiveX combobox in an ActiveX worksheet where I keep the remaining control, sometimes works well and sometimes it does not

Private Sub cboSelect_Change()
'Private Sub cboSelect_Initialize()
'cboSelect.Initialize
'cboSelect.Activate
Me.cboSelect.List = WorksheetFunction.Transpose(Sheet2.Range("B8:O8"))
End Sub
The lesson I follow says to doubleclick the cboSelect control and in the code window which will open to choose “Initialize”. But since I use an ActiveX control the only option I have is to write the code manually. If I choose a Form combobox in my ActiveX form the only option I have is to assign a Macro

How can I make it work?