there is no real documentation around snmp v3 traps in zabbix and how to set it up
for example net-snmp at least in Centos 7 is not supporting AES 256Bit encryption only 128 in zabbix we will not see warnings about it it will just not work
also the configuration in snmptrapd.conf is a bit different
authUser needs to have the execute option else the perl script will not be executed also the engineid is the engineid for the traps not the engineid configured on the switch.
there is also the option to send traps or informs with informs sending an ack back to the switch