After upgrading to Symantec PAM 4.1.4 the SNMP v3 user configuration was removed
I compared with another instance and noticed under Configuration > SNMP > SNMP v3 Users had a user on prod but was blank on the one I updated.
Release : 4.1
This is a bug in the PAM 4.1.4 upgrade scripts
You will need to readd the user to restart the SNMP services. This will be resolved in future patch updates.