When a username/password is set incorrectly for an SNMP item, instead of properly handling the error in configuration and marking the item 'disabled,' Zabbix misinterprets the SNMP response from the device as a network failure.

"failed: another network error, wait for 5 seconds" is logged and the entire device is taken out of service, instead of what should happen (e.g. the specific item is disabled and the reason for the particular item going to disabled status is that the SNMP username/password is incorrect for that item)