Workbook_BeforeClose event fires twice when Excel itself is closing

Hi folks, hoping someone can help me with this.

I have a workbook with a _BeforeClose event which fires twice, but only when the Excel application itself is closing. When the event fires the second time, the workbook is already "gone" from Excel and the objects it is referencing do not exist, leading to a runtime error.

When I close the workbook WITHOUT closing Excel, everything functions as expected.

As you can see, the Workbook_Close event and the doShutDown() function below both make calls to routines in other code modules. I have not supplied these here as there are a few. I have however tried removing these calls, but doing so does not fix the 'double-firing' behaviour so I think these can be safely eliminated from suspicion.

Private Sub Workbook_BeforeClose(Cancel As Boolean)

    If Now < ncb + TimeSerial(0, 0, 3) Then Cancel = True: Exit Sub

    Init.setGlobals False, False
    
    If [s_forceclose] = True Then
        If userID = Developer Then
            MsgBox "Would now close", vbInformation, dlt
            [s_forceclose] = False
            Cancel = True
        Else
            Cancel = False
            Me.Saved = True
        End If
    Else
        Cancel = Not doShutDown()
        If Not Cancel And Not Me.Saved Then
            If Application.userName = Developer Then
                Select Case MsgBox("Save?", vbExclamation + vbYesNoCancel, dlt)
                    Case Is = vbYes
                        Me.Save
                    Case Is = vbNo
                        Me.Saved = True
                    Case Else
                        Cancel = True
                End Select
            Else
                Me.Saved = True
            End If
        End If
    End If
        
End Sub

Private Function doShutDown() As Boolean

Dim sht As Worksheet

    If shtA.btnAdminCommit.Enabled Then
        MsgBox "You must either save or undo current user changes prior to closing the Roster Management System", _
               vbExclamation, dlt & " - Unsaved User Changes Detected"
        doShutDown = False
    Else
        Activator.lockApp
        With wbkRA
            .Unprotect sysPass
            shtNM.Visible = xlSheetVisible
            For Each sht In .Sheets
                If Not sht Is shtNM Then sht.Visible = xlSheetHidden
                sht.protect Password:=sysPass
            Next sht
            .protect sysPass, True, False
            With .Windows(1)
                .DisplayHeadings = False
                .DisplayHorizontalScrollBar = False
                .DisplayVerticalScrollBar = False
                .DisplayWorkbookTabs = False
            End With
        End With
        doShutDown = True
        Activator.unlockApp
    End If
    
End Function