My card doesn’t work - it has been rejected a few times, by works other times… help?
Maybe the location based security? Is your data roaming deactivated? What about the push notification of the decline? It usually tells you the reason why a payment was declined.
Check FAQs for how the security features work. Also: one can re-enable the card in the app in case it was deactivated because the system detected a suspicious and potentially fraudulent transaction.