I have also a different problem with commerce update with latest 1.14 version. After update via drush, order created and it reached checkout:shipping step, but when I do final order confirmation step, it stuck at payment page [checkout:payment] step, it shows blank page, actually I've skipped the checkout payment step on my previous 1.13 version and it worked fine.
what will be the issue? how to track drupal page and functions execution?