Aruba Client MAC Authentication Issue

Hello all, first post here for me but I'm running into a strange issue and wanted to see if anyone might have some insight.

I'm working with a client that is having issues with a device that won't content to their WLAN unless it's MAC is deleted from the controller's user-table. They do MAC authentication paired with PSK for these devices.

The device will associate to the SSID but never sends a MAC authentication request. Debug logs from the controller confirm this. I have them checking their authentication server to see if there's any entries for the affected devices and have also requested to see if their AAA profile for the group this device belongs to is configured correctly. Additionally I've requested they look to see if there's any IPS/IDS funkiness going on. As soon as the device is removed from the user-table, it will reauthenticate. It seems to me that there is something going on with their system not purging an entry for these devices, but I'm not familiar enough with Aruba to say that for certain.

I'm still a fairly new Network Engineer, having spent the bulk of my career to this point doing more end user support. I am eager to learn however. Any other avenues I should pursue on this? I can't share the actual debugs, otherwise I'd add them here as well.

Thanks!