Many people say that the problem is with the new AMD video cards, but I have a RX 580 8GB, before the update I always had fps above 63+, after the update I have 3/12 fps depending on the location, I opened a ticket and so far I have no answers, I tried several options without success, I even reinstalled the game and it continues the same way, I found a video on youtube about ( Addon Manager and DirectX 12 Guide for Guild Wars 2) made by
MuklukYoutube and I decided to test it, to my surprise 64/97 fps depending on the location, I don't know if it will work with everyone, but it doesn't hurt to try.