[Observium] Devices not being discovered

Hi all,

I've been running the CE version of Observium for a few years now, always upgrading as the new releases come out.

Earlier this year my server hosting Observium updated to Ubuntu 18.04 and php7x. As previously raised on list, this was incompatible with the previous CE version.

No problem, I waited it out.

Now my issue.

Since upgrading to the latest CE version, 5 out of my 7 devices (home network) are no longer being discovered.

I can confirm DNS is working. I've debugged as much as I can, including reinstalling snmpd on the Ubuntu boxes.

The devices which are staying down are my Ubuntu boxes and Unifi AP and Secure gateway.

Any direction on debugging would be greatly appreciated.