So you confirm that “Data Guard” and “Credit Card Numbers” are enabled in Security ›› Application Security >> Data Guard.
Then in “Security ›› Application Security : Policy Building : Learning and Blocking Settings” in advanced mode you can see " Data Guard " at the end of the page. you must set this settings to block.
Last point you confirm that your policy is in blockind mode (Security ›› Application Security : Security Policies : Policies List)