I have a catalog price rule that has been running for more than a month. We haven't had any issue with customers getting their savings. However, 2 orders came through recently in which the catalog price rule was not applied to the order after it was converted from the quote. Customers claimed the savings were visible during checkout, but they were charged full amount and no discount is shown in the order overview. The products they ordered were definitely on sale at the time of the problem.
Orders have come through since and between the two incidents with no issues.
While trying to debug the issue, my credit card was rejected, after which the catalog price rules were ignored and I saw full price items in the cart.
Payment method is Auth.net if that's any help.
Magento version 184.108.40.206
Is there any condition in which a quote would ignore catalog price rules?