You can not play the game in fullscreen it will crash your drivers audio will still play but graphics will feeze this has been an issue since launch
Run the game in borderless only
Use steam launch commands
-notexturesstreaming
Texture streaming has and will always be bad idk why games implement it
Go to lost ark.exe and disable fullscreen optimization this is more of a windows thing but it usually results in stuttering
Create a new chat in game and disable loot and all things that aren’t /area /party /raid or /say stops stuttering in chaos dungeons