How to reproduce this issue :
1 ) Define an action having Trigger severity >= Warning
The defauft message displays

{TRIGGER.NAME};{TRIGGER.STATUS};{TRIGGER.SEVERITY};{HOST.NAME};{EVENT.DATE};{EVENT.TIME};{EVENT.ID};{EVENT.STATUS}

2) Setup a trigger having a severity=High based on an zabbix trapper item
3) fire up this trigger with zabbix_sender = the result is OK : Action is performed and {TRIGGER.SEVERITY} provided by action is High
4) recover trigger using zabbix_sender : the result is OK : Recovery Action is also performed and {TRIGGER.SEVERITY} provided by action is High

So in less than 30 sec try this :
5) modify the trigger severity using interface or API from High to Not Classified
6) fire up again this trigger with zabbix_sender = the result is NOTOK : Action is performed and {TRIGGER.SEVERITY} provided by action is 'Not Classified' even if Action condition is still Trigger severity >= Warning

==> Because Trigger severity is now Not Classified, action should normally not be activated !

7) recover trigger using zabbix_sender : the result is NOTOK : Recovery Action is also perfomed and {TRIGGER.SEVERITY} provided by action is 'Not Classified'

That means Action condition does not work correctly when Trigger severity has just changed