OK, this version doesn't have that issue but won't retain other formatting into the duplicate.
Code:
Sub TranslationPrep()
Dim iPar As Double, aRng As Range, aPar As Paragraph
Dim iCount As Double, aRngAdd As Range, iExtra As Integer
Dim sPar As String
With ActiveDocument
For iPar = .Paragraphs.Count To 1 Step -1
Set aPar = .Paragraphs(iPar)
Set aRng = aPar.Range
If Len(Trim(aRng.Text)) > 2 Then
Set aRngAdd = .Range(aRng.Start, aRng.Start)
sPar = Trim(Split(aRng.Text, vbCr)(0))
aRngAdd.Text = sPar & vbCr
aRngAdd.Font.Hidden = True
With aRng.Paragraphs.Last.Range
.Font.ColorIndex = wdBlue
.ListFormat.RemoveNumbers NumberType:=wdNumberParagraph
End With
End If
Next iPar
End With
End Sub