Upgrade to PAYG blocked: cards instantly declined by Oracle Pay, no bank auth - SR 260806-000399

Hello Oracle team and community. My tenancy densirein (home region Mexico Central/Queretaro, account denis@rein.cr, account type Promo, plan reference 29350004, Free Tier since Jun 14, 2023) cannot be upgraded to Pay As You Go for about 3 months. Symptoms: on the Upgrade and Manage Payment page the subscription shows Payment Method "-" with the warning "Add a payment method to upgrade a subscription plan". The Oracle Pay dialog still holds my OLD cancelled card (VISA ending 3411) as the only stored payment method - that card was replaced by my bank. Adding any new valid card (multiple cards, different issuers,