Have you added that tracking to where you marked the item as dispatched? If not do so now.
When tracking shows delivery, your payout will be released 2 days after that delivery order.
Royal Mail tracking is sometimes not in sync with eBay's tracking, and the latter is the most important for releasing a faster payout, that is, 2 days after the delivery date.
If you have found your tracking has not updated, therefore holding back your payout, contact eBay Customer Services, provide the tracking showing delivery, ask if they can kindly release your payout now as 48 hours have passed the delivery date.
This is the easiest and quickest way to contact eBay Customer Services, for a Call Back option.
https://www.ebay.co.uk/help/eua?id=5275&mkevt=1&mkpid
Lines open between 8 a.m. to 10 p.m. on weekdays.
9 a.m. to 6 p.m. on weekends.
I recommend contacting CS very first thing in the morning, when the lines first open, as there's more chance of Dublin answering.
With no tracking, your payout will be held for 14 days.
@equestrianfan