I've seen a possibly related issue with static electricity in a large building in PA that had 3 power feeds, after lightning we would have ethernet port problems.
I would suggest that you declare a 2am Thursday maintenance window and use a script to automatically reboot all the devices. This in combination with checking that you have a good separate ground wire connection at all antenna locations should pretty much fix it. The reboot cycles the power and should hopefully drain anything extraneous.
That sounds like a great idea. I've actually debated doing this before, but I wasn't sure if the service disruption was worth it considering it happens maybe once every other month and sporadically at that.
I ran a bootstrapped ISP much the same way. I ran into the static issue as well did a few things to fix it. Ran a better ground on the roof. Isolated the tower from the roof surface with wood (that was done during tower erection). Lastly, I put a fiber link cut in-between the run of Ethernet from the data center, and the router box on the tower.
I did a bunch of ISP builds in my younger days. It is worth while to see if you can horse trade some internet for an electrician with tower experience (or a real RF engineer) to help you.
As other commenters have suggested, check your ground potential and make corrections as necessary.
Unless I open up the device, there's nothing to attach ground wire to. The device is constructed primarily of plastic. Grounding the dish wouldn't do anything, would it?
You could make the maintenance once a month on days your monitoring shows already have about no traffic. If a HA setup, then fail-over, reboot main, fail-back-over, reboot other stuff. Minimal disruption there.
If you've got an HA setup you should probably be doing this monthly anyway just to verify that it actually works. The adage that an untested backup isn't a backup at all applies to backup internet connections as well.
Er, does it? Some of the components might go offline, but there's usually still a trickle-charge running to the components even when the computer is "off"—and especially the ethernet card, for Wake-on-LAN support (even if it's disabled.)
I would suggest that you declare a 2am Thursday maintenance window and use a script to automatically reboot all the devices. This in combination with checking that you have a good separate ground wire connection at all antenna locations should pretty much fix it. The reboot cycles the power and should hopefully drain anything extraneous.