I have been running OPNsense for 3+ years, and unfortunately due to heavy snow, a power line went down and sent a surge up the cable line. This let the magic smoke out of the modem, Cat6 cable, and the router running OPNsense.
Fortunately, I take nightly backups, and after getting new (identical) hardware (Protectli FW2B) I was able to install OPNsense and upload my config.xml.
I am running the latest download iso, and we still don't have a main internet line to update any packages, as that line was melted.
However, while the backup worked, the original static DHCP listings seem to be missing - I set them up back in the day when they were called DHCPv4 under the Services menu, but now I only see the KEA DHCP and no other options.
This is a problem, as many devices are not seeming to get their static DHCP leases back, and I cannot remember what I set them to all those years ago.
Where should I look for these settings?
Also, given that I currently have no internet, will OPNsense try to get the missing packages I installed prior when I do have WAN again? That is, does the config.xml remember the Plugins I had and can pull them again?
You probably installed a newer version of OpnSense where ISC DHCP has become a plugin. Once you have internet backup, you can reinstall the package and get everything up an running again.