Anyone interested in comparing (US order) Order Page totals, View Order details to MP Page totals, Send Invoice Totals/Invoice sent email, create Packslip eBay Totals (ebay), Packslip Shippo Totals, knock your socks off. Discrepancies are caused by tax rounding and when eBay has chosen to or not include taxes(Collected by eBay but charged to customer) in the final total.
As far as accepted business practices go, there should ALWAYS be consistency in how information displays for any transaction. This information is for buyer/seller and eBay purposes. Not just eBay's !!!
-Lotz