Order item not added on webform submission resulting in failed access check in CheckoutController::checkAccess

Problem/Motivation

When I try to submit the webform I created, there's no order item attached to it so it fails here:

\Drupal\commerce_checkout\Controller\CheckoutController::checkAccess

I don't know if this is just a misconfiguration on my part or if something is actually broken. I've attached that config.

I also noticed the documentation is somewhat out of date relative to the UI.