Hello! We are having a issue with the UPS rates not allowing the customer to go past the shipping options section on the checkout page. The rates are correct and you can select them however when I click continue to go to the next section (Payment Method), it does not allow me to go to the next step and display the message "UPS rates have changed". The really weird thing is it is intermittent and sometimes allows us to go to the payment method.
For testing we switched from the UPS rates to the FedEx rates in the admin (Bypassing UPS rates) and it works without issue.
My best guess is that this is a conflict with the UPS servers and CS-Cart. Has anyone else come across this type of issue?
Thank you for any feedback.