The authorized MAC address on a port that is configured for both 802.1X and port security either changes or is re-acquired after execution of aaa port-access authenticator <port-list> initialize

If the port is force-authorized with aaa port-access authenticator <port-list> control authorized command and port security is enabled on the port, then executing initialize causes the port to clear the learned address and learn a new address from the first packet it receives after you execute initialize.