Discrepancy Between Trial Period Pricing Display and Billing Amount

I am writing to report an issue we've encountered regarding the trial period pricing and the billing amount in the ARMember system. Here is a detailed description of the problem:
The issue is consistently reproducible.

New Subscription Registration

During the registration for a new subscription, the trial pricing was correctly displayed and billed at half price, as expected.
Changing to a Different Plan

Upon changing to a different plan, the front-end display and PayPal showed the regular price, but the "Payment Report" indicated a charge at half price. This results in a discrepancy where the display shows half price but the actual billing is done at the regular price.
This inconsistency between the displayed trial pricing and the billed amount is causing confusion. We are unable to determine the correct application of trial pricing conditions within the ARMember system, and it is unclear which pricing (half or regular) is intended to be correct.

We kindly request your assistance in resolving this issue. It would be greatly appreciated if you could clarify the correct conditions under which trial pricing is applied and make the necessary adjustments to ensure that both the displayed pricing and the billing amount are consistent.

Thank you for your attention to this matter. We look forward to your prompt response and a resolution to this issue.