Hello David, thank you. I use the Generatepress-Child. I did this and it worked: I put a folder-structure into my child-theme: woocommerce > myaccount >orders.php . I pasted the code and deleted those three lines (thank you for highlighting). The folders have 755 and the orders.php has 644 permissions. Thanks for the great advice, very very easy solution.
But..: same thing with “woo-subscriptions”: I looked up the my-subscriptions.php and I guess it is the same thing all over. Thanks Klaus