Update Payment in eBay
You can update the payment status directly at eBay from Odoo. Go to menu eBay / Sales / Invoices and filter out the Paid invoices. Now select any invoice among those paid invoices for which you want to update Payment status at eBay and click on the Update Payment in eBay button.
Here, an important thing to note down is that button for update payment in eBay will be visible only when the invoice is 100% paid, and in the payment option of related Sale Order of that Invoice, you have allowed updating payment in eBay by setting the value of the checkbox Update payment in eBay to True.