Do you disconnect your FTTC modem and router from the mains/BT socket when a storm is forecast? My line is wholly underground back to the cab some 500m with houses along the entire length; but I read that might be worse than an overhead line for susceptibility to lightning strikes? (Historically the modem reports between a few hundred and a thousand or so errors ph (compared to less than 30 ph normally) during lightning within visible range, viz several miles; but with no other ill-effects on the connection). But I've not heard of any neighbours getting their modem/routers fried and I am located within a housing estate, though on a hill and at just about the highest point. The Church within a couple of hundred metres has a lightning conductor if that makes any difference. (I've always disconnected the telly aerial anyway).
It hasn't been a problem the last few years, for me, but now we seem to be having the odd flash and crash several times every other day, and I might be getting neurotic or something, but I end up manually connecting and disconnecting like the proverbial yo yo. I'm beginning to think I might as well give up on the PC between April and October anyway, and just stick with the mobile data through the smartphone!