Game freezes only in dungeons

[sitarskee.5738]

Hi,

I get this weird issue lately that my game starts freezing every few seconds when I am in dungeons which makes most of them unplayable. I haven't had this issue before and it only appears in dungeons and sometimes in story even though I believe they're less demanding than playing WvW with big zergs where I do not freeze like this at all. Has anyone had this issue? Does anyone know what could cause it? I don't have any addons installed, game runs smooth except for this case.