Userform cannot display info for two surnames that is the same from dropdownlist

I using this code to get data from dropdown list

But if I have two surnames that is the same, I cannot get it to show the correct data from each same surname, it show the first name of the first person of the first same surname.

So if say if the first same surname is Pienaar with two names (Piet and Sannie) and second same surname with two names (Jaapie and Sarie, so when I choose any same surname it show 3 names showing (Piet, Sannie and Jaapie).
only happening with same surname. It must show only the name or names of each same surname.

Private Sub cboSurname_Change()
    Dim ws As Worksheet
    Dim lastRow As Long
    Dim i As Long
    Dim surname As String
    Dim surnameRows() As Long
    Dim surnameRowIndex As Long
    Dim memberIndex As Long
    
    Set ws = ThisWorkbook.Sheets("Register")
    lastRow = ws.Range("D" & Rows.Count).End(xlUp).Row
    surname = Me.cboSurname.Value
    
    'Clear the existing data in the controls
    ClearControlValues
    
    'Find all the rows with the selected surname
    ReDim surnameRows(0)
    surnameRowIndex = 0
    For i = 10 To lastRow
        If ws.Range("C" & i).Value = surname Then
            surnameRowIndex = surnameRowIndex + 1
            ReDim Preserve surnameRows(surnameRowIndex)
            surnameRows(surnameRowIndex) = i
        End If
    Next i
    
    'Populate the controls with the information for all the rows with the selected surname
    memberIndex = 1
    For surnameRowIndex = 1 To UBound(surnameRows)
        Me.Controls("txtNaam" & memberIndex).Value = ws.Range("D" & surnameRows(surnameRowIndex)).Value
        Me.Controls("txtverjaar" & memberIndex).Value = ws.Range("E" & surnameRows(surnameRowIndex)).Value
        Me.Controls("txtselfoon" & memberIndex).Value = ws.Range("I" & surnameRows(surnameRowIndex)).Value
        
        memberIndex = memberIndex + 1
        If memberIndex > 5 Then
            Exit For
        End If
    Next surnameRowIndex
End Sub

Private Sub ClearControlValues()
    Dim i As Long
    
    For i = 1 To 5
        Me.Controls("txtNaam" & i).Value = ""
        Me.Controls("txtverjaar" & i).Value = ""
        Me.Controls("txtselfoon" & i).Value = ""
    Next i
    
    Me.txtHuis.Value = ""
    Me.txtWerk.Value = ""
    Me.txtadres.Value = ""
End Sub

Private Sub PopulateSurnameDropdown()
    Dim ws As Worksheet
    Dim lastRow As Long
    Dim i As Long
    
    Set ws = ThisWorkbook.Sheets("Register")
    lastRow = ws.Range("C" & Rows.Count).End(xlUp).Row
    
    'Clear the dropdown list
    Me.cboSurname.Clear
    
    'Populate the dropdown list with unique surnames
    For i = 10 To lastRow
        If Not IsEmpty(ws.Range("C" & i).Value) Then
            Me.cboSurname.AddItem ws.Range("C" & i).Value
        End If
    Next i
End Sub