See title. It is no lightning effect, as it appears in all environments, regardless of camera position and so on. Changing graphics settings doesn't change anything too.
https://i.postimg.cc/DyCj8t86/GW2-Bug01.png
https://i.postimg.cc/NfL8PLj8/GW2-Bug02.jpg
https://i.postimg.cc/rsH4LCw1/GW2-Bug03.jpg