https://docs.librenms.org/Extensions/Auto-Discovery/
How do you have auto-discovery setup? Keep in mind auto discovery only runs every 6 hours or depending on when you added the device.
Did you configure SNMP? https://docs.librenms.org/Extensions/Auto-Discovery/#snmp-details
Did you configure the nets its supposed to scan? https://docs.librenms.org/Extensions/Auto-Discovery/#allowed-networks
also if you don’t fqdn for your device I would suggest enabling this
$config['discovery_by_ip'] = true;
https://docs.librenms.org/Extensions/Auto-Discovery/#additional-options