Steps to reproduce:

1. Add trapper item 'trap_001'
2. Add trigger 'trig_001'
   ltrim(last(/Zabbix server/trap_001),"а")="Заббикс"
3. Send data by sender
   bin/zabbix_sender -z localhost -p 10051 -s 'Zabbix server' -k trap_001 -o 'аЗаббикс'
4. Check that trigger fired

Result:
Trigger didn't fire
Expected:
Trigger fired