SNMP subagent not registering

Setting up some new AlmaLinux 9 boxes running Asterisk 16.29 and NET-SNMP 5.9. I’m unable to query snmpd for Asterisk stats. This same config works without issue on some (much) older servers running Scientific Linux 6.10, Asterisk 11.9, and NET-SNMP 5.5.

Has anyone had any success using SNMP in an EL9 environment? I’m just hoping I don’t have to get out gdb to get to the bottom of this…

AgentX support is enabled in snmpd.conf:

master agentx
agentXSocket tcp:localhost:705

I can see it listening on TCP 705:

$ ss -plant
State    Recv-Q   Send-Q   Local Address:Port    Peer Address:Port   Process                                                        
LISTEN   0        5        127.0.0.1:705         0.0.0.0:*           users:(("snmpd",pid=85464,fd=9))

Module res_snmp.so is successfully loaded and the agent activated:

[2022-11-22 12:12:42] VERBOSE[84867] loader.c: Loading res_snmp.so.
[2022-11-22 12:12:42] VERBOSE[84867] res_snmp.c: Loading [Sub]Agent Module
[2022-11-22 12:12:42] VERBOSE[84867] loader.c: res_snmp.so => (SNMP [Sub]Agent for Asterisk)
[2022-11-22 12:12:42] VERBOSE[84913] snmp/agent.c: Starting SubAgent

But I see no subagents registered when I try walking the nsModuleTable MIB, and there are no active connections to TCP 705.