Hi,
Configuraiton mismatch tigger will help only if it detect mismatch in configuraiton between Airwave and Controller. If device is in Good configuraiton state in Airwave and it is in monitor mode and some one tried to make changes and applied. Configuraiton will not get pushed to device and config status will shows as mismatch in Airwave and in this case it will trigger an alert but if device is in manage mode and someone pushed the config and status changed from config in progess to good after configuration get pushed to device it wont notifiy.
We can try set trigger based on event, like "Configuration verification succeeded" or In progress etc... For exacxt event you can check the event section of controller/IAP APs/Device>Monitor page during config push.
To check what config changes is been made then we need to look device-config log.