When dealing with a failed 802.1X authentication attempt to a WLAN enforced by Aruba ClearPass Policy Manager (CPPM) where no record of the attempt is seen in ClearPass Access Tracker, a good next troubleshooting step is to check the CPPM Event Viewer. Since you are able to successfully ping from the Mobility Controller to CPPM, this indicates that there is network connectivity between these two devices. The lack of a record in Access Tracker suggests that the issue may not be with the RADIUS/EAP certificate or user credentials, but possibly with the ClearPass service itself or its reception of authentication requests. The Event Viewer can provide detailed logs that might reveal internal errors or misconfigurations within CPPM that could prevent it from processing authentication attempts properly.