Steps to reproduce:

1. Create Zabbix trapper item with key: trap, data type = character
2. Create trigger for the item, with expression: last(/host/trap)<>0
3. Use macro function in event name and OP data for the trigger:

   {{ITEM.VALUE}.regrepl("([^a-z])","\\\1")}

4. Send value

   {ITEM.VALUE} = TEST 012345
   

5. See event details

Result:
Event name (resolved by server): \T\E\S\T\ \0\1\2\3\4\5
OP data (resolved by frontend): \T\E\S\T\ \0\1

Expected:
Frontend should resolve macro function same as sever