The issue lies with you, rather than Ebay.
Only private sellers have to use Simple Delivery.
Only business sellers sell all brand new items and create custom orders.
If you register correctly as a business seller, you will be able to communicate with your buyers to receive details of their orders.
https://www.ebay.co.uk/sellercentre/selling/create-ebay-business-account
"There are two ways to be fooled. One is to believe what isn't true; the other is to refuse to believe what is true.”
Søren Kierkegaard, Danish philosopher (1813 - 1855)