SNMP getting blocked by ASA recently

I have 2 ASA's in 2 different locations, with a Barracuda Link Balancer in front of each one. As of recently, all 4 of the devices are showing "Unknown" for all of their interfaces. I tracked this down to it being an issue with SNMP. I can't connect to any of them via SNMP(The test in the Node Properties screen fails). And then I came across this article:

SolarWinds Knowledge Base :: Why are my interfaces changing to "unknown" status, even when I know they are active?

My question is, what exactly do I need to configure on the ASA to get it to pass SNMP traffic again. The article states that rebooting the Orion server will fix the issue, but that's not working for me either.

Does anyone else have any ideas what might be causing this?