Net-SNMP Temporarily Stops Responding?

[PhYrE]

Hopeful someone might have run into this and can help point me in the right direction.

Have OPNsense on physical hardware, with both public and private and provider nets on it.  Net-SNMP is listening on only the private Net on one internal IP. 

About once a week, for about 2.5 hours:

Net-SNMP has started simply not responding (timing out) to MRTG. It simply resumes on its own with no interaction or involvement after maybe 2.5 hours.  This happens for all targets (interfaces) on OPNsense [ie: \igc4:MYSECRET@10.100.70.1:::::2 / \lagg0:MYSECRET@10.100.70.1:::::2 / \wg0:MYSECRET@10.100.70.1:::::2].

MRTG works for all other hosts it polls.  There is no configuration change in it from when it was working.  We see it in the logs for MRTG with OPNsense timing out and any other router/server processing correctly.

OPNsense continues to route 15-20Mbps of traffic problem-free during that time, answer DNS queries, and do everything else it is supposed to.  Reporting|Health shows normal traffic on all interfaces during this time.  Processor load is about 6%.  States, CPU temp, memory (12% used), etc are all fairly constant.  Disk is used 2%.

There is nothing I have found in the logs on why it might not respond to SNMP requests.  The fact that it just starts working again hours later takes me away from configuration issues.  The fact that the host is otherwise accessible takes me away from thinking anything is wrong on the networking side.

Any insight on where I might look next?