Less smoothness in The Riverways, near The Root of the Problem

Yesterday I was walking around in the Riverways, just killing packs etc. I had a constant FPS which allows me to run the game smoothly, even when there's a total chaos with 100 mobs.

When I came near the Root of the Problem quest, I suddendly noticed the game to become way less smooth. I thought there would be a FPS drop, but my FPS remained the same. It only happened in this small area. Even when I wasn't fighting any mobs at all.

Perhaps there is some minor scripting issue or something? I managed to reproduce this by going back a couple of times, each time the game became slower. When I left the particular area everything went back to normal.

Would be a waste if anyone died due to this (minor) "bug". Or at least it seems like a bug to me.

there are more enemies around the tree entrance in riverways which need to be instanced on your client when you move next to this area and they get into line of sight.

so depending on your computer this loading of textures and stuff from your harddisk can make you move more slowly.

from my experience these problems got away when i bought a ssd, no delay when loading instances or moving through them since then.

I have an SSD (also a decent graphics card, i7 processor, sufficient RAM etc) that works fine, my FPS doesn't drop - which imo should be a good indicator of an actual PC issue.

It also occurs when I have completely cleared the mobs around that area.

Bigger packs in other areas don't slow me down like this.