Error 2042 using Application.Match to add item and update combobox list

Hi all

I have the following code that adds a new item to a combobox list

Private Sub ConfirmNew_Click()
            
    Dim idx As Variant
    Dim rng As Range

    With Worksheets("Module Data")

        Set rng = .Range("B2", .Range("B" & Rows.Count).End(xlUp))
    End With

    idx = Application.Match(NewGarage.Value, rng, 1)

    If Not IsError(idx) Then

        rng.Cells(idx + 1, 1).Insert xlShiftDown

        rng.Cells(idx + 1, 1).Value = NewGarage.Value

        Garage.List = rng.Value

    End If
    
End Sub

The list of Garage names is in sheet "Module Data". A new Garage name can be inserted in a Textbox "NewGarage".

The code successfully inserts a new name in alphabetical order.

However, if the new name is above the first alphabetically listed name, it gives an error (2042). The workround that I did was to put a dummy name "AAAAAAA" first in the list and the code works.

Can anyone suggest why this is so and what can be changed in the code to add the new name at the top?

Thanks