Not seeing that behaviour here but maybe one of these will help:
Sub ScratchMacro()
Dim oPar As Paragraph
Dim strNum As String
Dim lngIndex As Long
For lngIndex = ActiveDocument.Range.Paragraphs.Count To 1 Step -1
Set oPar = ActiveDocument.Range.Paragraphs(lngIndex)
strNum = oPar.Range.ListFormat.ListString
oPar.Range.ListFormat.RemoveNumbers
oPar.Range.InsertBefore strNum & vbTab
Next lngIndex
End Sub
Sub ScratchMacroII()
Dim oPar As Paragraph
For Each oPar In ActiveDocument.Paragraphs
oPar.Range.ListFormat.RemoveNumbers
Next oPar
End Sub