Added codes to macro and some codes no longer work

I have an Excel file that tracks engine status from Sales and Production departments. Columns A - M in the workbook contain data necessary to deem the engine status. Columns N - AR are used to track engine status with the following column order: Sales, Production, Day 1, Status. That repeats till Day 8 (i.e. Sales, Production, Day 8, Status).

Column AV is called "MB51 Shipped" and column AY is "Title Transfer".

I have 2 requests for the Macro such that:

1) If "Shipped" in column AV, then the empty remaining Days will have "Rollup" in both Sales and Production columns.

I got helped by someone on this and he recommended to add the following codes to "Master Worksheet":

Dim lastColumn As Long
Dim counter As Long

Application.EnableEvents = False

' Check if header is "MB51 Shipped"
If Me.Cells(1, Target.Column).Value = "MB51 Shipped" Then

    ' Get last column based on first row
    lastColumn = Me.Cells(1, Me.Columns.Count).End(xlToLeft).Column

    ' Check all cells in row and find matches for Sales and Production
    For counter = 1 To lastColumn

        ' Check if header match and cell is not empty
        If (Me.Cells(1, counter).Value = "Sales" or Me.Cells(1, counter).Value = "Production") And Me.Cells(Target.Row, counter).Value = vbNullString Then

            Me.Cells(Target.Row, counter).Value = "RollUp"

        End If

    Next counter

End If

Application.EnableEvents = True

It seemed to work as first but then I noticed the Day cells didn't return anything even though originally my macro DID return correctly the values based on IF statements. Can you please advise how I can fix this?



2) If the last entered Sales cell says "Title Transfer" then return "x" in column AY (51st column)


Any help is greatly appreciated! Thank you!!!!