search cell values from textbox value on userform

Hello, I am confused with this one. What I want to happen is that when a person is entering a name into a textbox on a userform they will be given suggestions of a name(s) previously entered. What I already have is when people press submit, the name in the testbox "Guestname" the value is placed on a cell on Sheet1 and on Sheet11. Sheet11 ("Total Guests") is where I want the textbox to scan names to provide suggestions. Is this possible?

On Sheet11 the names are listed from Column A, Row 2 all the way down. Here is the current code I have, but it just keeps kicking me to Sheet11 and not doing what it used to do.

Private Sub Guestname_BeforeUpdate(ByVal Cancel As MSForms.ReturnBoolean)
Dim test1 As String
Dim FoundRange As Range
     
    test1 = Guestname.Value
    Sheet11.Activate
     
    Set FoundRange = Sheet11.Cells.Find(what:=test1, LookIn:=xlFormulas, LookAt:=xlWhole)
     
    If FoundRange Is Nothing Then
        Guestname.Text = FoundRange.Value
    End If
End Sub