Logging of AP activity is handled by Mfeann.exe.
Is this process running?
If it is running, is naiann.dll a loaded module inside that process?
You can use Process Explorer to verify.
If these show "no issue" then you should reproduce triggering the event to occur while ProcMon is running. That will show you if there's even an attempt to write to the log file. Or, perhaps it is writing to a log file in an unexpected location. Procmon will show it.
Depending on your findings you may need to contact McAfee Support to find out what's broken with the installation.