Hi folks,
We were running into a problem where upon clicking "Checkout" button, we kept getting sent to a URL starting with https://trans.atsbank.com which was some sort of form.
We looked into it a bit and found out that this is a WonderPay functionality. We also found this link below on the main Drupal site where someone else had the same problem:
We added a comment about how to fix it. See the above link.*
Kim and Chuck
* Spoiler: disable "WonderPay redirect" in "Checkout Settings"!
