Add page break before cell which contains specific text

In case this helps anyone else I figured it out. I had to reset the breaks first. Here's what worked:

Sub PB()


 Dim xWs As Worksheet
 Dim val1 As Variant
    
Set xWs = ActiveSheet

xWs.ResetAllPageBreaks

For Each val1 In Columns("A:A").SpecialCells(xlCellTypeConstants)

    If Left(val1.Value, 4) = "MBU:" Then

         ActiveSheet.HPageBreaks.Add Before:=(val1)

    End If


  Next
  End Sub