SNMP Traps only work via proxy for some devices?

[Clontarf[X]]

Based on 3 SNMP traps (zabbix.com), the trapper needs hosts with an SNMP interface with matching IP or DNS (based on the interface configuration). I have some hosts in Zabbix that although the SNMP interface is attached, with the right IP, and the incoming trap source IP matches, they still get logged as unmatched traps. In this case, the hostname does not match (is a discovered hypervisor via HV.GUID).

Even weirder is that if I set other hosts that have the same issue to be monitored by a Zabbix Proxy, the traps work without further configuration.

What is happening here? We're about to migrate away from LibreNMS so we need to ensure that incoming traps are understood. Why isn't Zabbix able to match traps that come directly to Zabbix Server for some devices?

[cyber]

Traps need to come same way as the host is monitored.. If host is monitored by proxy, then your traps need to come through that proxy. If monitored by server directly, then traps need to arrive directly to server.