I have setup a SNMP trapping on my Zabbix 4.0.3

My problem is with getting Recovery trigged as It comes with a ' in the text. I tried to add \ but it doesn't work.

I'm using a Item KEY : snmptrap["Status Events"], I put a trigger 
Problem: {Template SNMP TRAP:snmptrap["Status Events"].str(appliance service down,1)]=1
Recovery:{Template SNMP TRAP:snmptrap["Status Events"].str(\'appliance service down\' is cleared,1)]=0

how the snmp log is incomming :

10:21:22 2019/01/22 .1.3.6.4.1...... Normal "Status Events" 192.168.10.25 - Appliance Alert : 'appliance service down' is cleared.
10:19:22 2019/01/22 .1.3.6.4.1...... Normal "Status Events" 192.168.10.25 - Appliance Alert : appliance service down

I know I can change the snmptt file to remove the ' in the text but I would link to understand why the \' is not working with snmptrap

Thanks