I can't see how the error "loadSomething::planid 116 of subid 20025 does not match planid 133." could be dependent on the credit-card type. That error is probably due to some heavy changes in the plans, and possibly some direct changes to the subscription or even in the database, and could be an old error. You can check the subscription 20025 in the Subscriptions, by clicking on its id, and fix the plan id it belongs to..

Regarding difference in behavior between Visa and MasterCard, please contact Authorize.net, as API-wise they are identical.

Thank you for the feedback, I wasn't aware that there was a PHP 5 issue in authorize.net, but still can't explain why it affects Mastercard but not Visa.

We are considering of completely dropping support for PHP 5.6, as it now obsolete and non-security maintained for years.