I got this message after click save:
Our systems detected that at least one of your forms requests for sensitive information. To minimize abuse and malicious use of our service, we can’t allow you to continue using unprotected fields to collect such data.
Upgrade to the Plus Plan and use encrypted fields to unblock this restriction.
If you’re collecting credit card data, contact us so we can enable Vault

CI Add-On Package on your account and you can continue collecting cc info according to PCI standards.