You configured devices to send SNMP traps to NPM, but do not see the messages...

The SNMP trap service is responsible for receiving, decoding, displaying, and storing the SNMP trap messages in the Log Analyzer database. If the service is not running, you will not see the messages in the Orion Web Console. You can verify the status of the service by using the Orion Service Manager or the Windows Services console. You can also restart the service if needed. The other options are not relevant for troubleshooting the cause of missing SNMP trap messages. References:

Monitor SNMP traps

Troubleshoot SNMP traps

Orion Service Manager