This worked for one of my buyers a couple of hours ago, but another buyer does not seem to be able to replicate it. It may be worth a try.
Use a desktop version of eBay - not the app.
"I used the Add to Cart option not Buy it Now.
I then went to the Cart symbol and clicked and a Go to Checkout option came up.
I did that and in the top right was a Request Total to obtain a combined shipping invoice.
It advised that by asking for this you commit to buy.
Once I did that they showed up as sold in my Watch List."
That generated a message to me - Action needed: Send an invoice to your buyer. Which I did.
