That is not possible anymore, if you have posted together several item purchased separately.
Only one tracking number will show, so payout for one item after buyer pays, will be received.
The other 4 payouts may take a minimum of 14 days to be released.
Combining postage has been, and frustrated many, a technical issue now for a long time with Simple Delivery and combining postage, it's just not possible.
For future purchases like this, the best way forward would be to cancel all items, of course, with the buyer's acceptance, and relisting them as one, so there's one important tracking number, one postage price. Ensure any message to your buyer makes it very clear the reason why the items are being cancelled, that they are to be relisted on eBay again, for the buyer to buy, leave no room for doubt that this is Not an off eBay sale.
Some sellers are leaving a message on their listing, for example..... ' If you wish to buy multiple items, please let me know before buying, I will relist them as one listing so only one postage cost is charged, combining postage is not currently possible. '