Same here, since yesterday's maintenance(the 2 hours long one), I have gamebreaking latency issues, I can't even play since when aoe appears, i'm already dead(not just on the verge of dying, but dead).
Server : Ragnarok
ISP : numericable
Country : france

It happens at all times , I tried yesterday afternoon, evening and this morning, the result is the same.
I didn't have much latency related issues before, only a few rare freezes every now and then and the "normal" latency considering that the servers are a bit far from EU.