Performance issues in specific locations - Shaders related or GW2 Hook

In some rare locations, my fps can drop from 60+ to around 20-25 or so. I've found that by lowerin shaders to low or medium, and then back up to high again resets this fps drop in these places. Since I'm running GW2 Hook, I'm not sure if it's related to the addon, of if this is a general issue in the game.

I would be interested to hear from other players here if they can try this method in places where they experience fps drops, to see if the 'switching shaders quality' method works for them as well to restore higher fps, and if so, if you're running GW2 Hook or not. Thanks!