This is version 6.4.0 (from ports)

Steps to reproduce:

1. Create discovery item w/ trigger
2. Add expression to even name. ex: {HOST.NAME}: {#DEVICE}: non medium error: +{?change(/disk/non_medium_error-sea.sas-[ {#SER}

   ])} ({ITEM.LASTVALUE})

3. Add discovered items using zabbix_trabber

Result:
event name (of discovered item) does not replace template path with host path for item:

Ex: {HOST.NAME}: da80: non medium error: +{?change(/disk/non_medium_error-sea.sas-[ZA17Z28M])} ({ITEM.LASTVALUE})

Expected:

: da80: non medium error: +{?change(/MYHOST/non_medium_error-sea.sas-[ZA17Z28M])} ({ITEM.LASTVALUE})

When triggered the event name appears as:

MYHOST: da80: non medium error: +UNKNOWN (1234)