Similar thing happen to me. Had a lightning strike fry the ONT port outside, the charge went through to the UPS cat5e surge protector and to my opnsense box and fried it. Luckily it stopped there.

This is where I tell everyone to never buy UPSs from CyberPower. I sent them the thing to inspect because it was guaranteed paying for the damages from power surges and they claimed there was nothing wrong with it and their inspection came clean. But they sent me a new one and said they won't pay for my lost firewall.

Sorry to hear you got 10k in damages, that sucks. I've now got a whole house surge protector to try my best to avoid that (and I STILL unplug expensive things like my TV and stereo system).