VBA: Sheet formatting and formulas disrupted upon insertion of many rows

Question

I am trying to create a VBA code in which user can insert multiple rows at the click of a button in a protected sheet. The number of rows to be inserted depends on user input. The code below works fine for 1-4 rows.

For insertion of 5 rows and above, the code will still run and correct number of rows will be inserted, but the formatting of the table and subtotal formulas at the bottom of the table will will be disrupted.

Some examples of the disruptions include, the borders disappearing for some cells and color fills overrunning into other cells that are not meant to be colored. The subtotal cells will also show "#VALUE!". I'm using INDIRECT function in the subtotal cells to take into account addition of new rows.

Would appreciate any help on this!

Code used:

Sub InsertRows()

    Application.ScreenUpdating = False
    
    ' Unprotect the sheet
    ActiveSheet.Unprotect "abc123"

    Dim numRows As Integer
    Dim counter As Integer

    'Select the current row
    ActiveCell.EntireRow.Select
    On Error GoTo Last
    numRows = InputBox("Enter number of rows to insert", "Insert Rows")
    
    'Keep on inserting rows until we reach the desired number
    For counter = 1 To numRows
    Selection.Insert Shift:=xlToDown, CopyOrigin:=xlFormatFromRightorAbove
    
    ' Fill down the formula from above the inserted row to below it
    Range("F" & (ActiveCell.Row - 1) & ":F" & (ActiveCell.Row + numRows)).FillDown 'Total SP
    Range("J" & (ActiveCell.Row - 1) & ":J" & (ActiveCell.Row + numRows)).FillDown 'Unit Cost
    Range("K" & (ActiveCell.Row - 1) & ":K" & (ActiveCell.Row + numRows)).FillDown 'Total Cost
    
    Next counter

'ExitHandler:
    ' Protect the sheet again
    ActiveSheet.Protect _
        Password:=("abc123"), _
        AllowFormattingColumns:=True, _
        AllowFormattingRows:=True

Last:    Exit Sub
    Application.ScreenUpdating = True

End Sub