The game does not allow you to choose to resist or to swear fealty. you can use all abilities and type g and h in the chat channel but pressing the buttons does not activate the choice thus leaving you stuck in a main story quest line. guess i will just not have to play till its fixed since it stops anymore playing of the game.
update. i reinstalled the game and the quest was able to continue past the story point that it was previously bugged at.
Enabling Vsync in Nvidia Control Panel for this game fixed the problem for me.
Manage 3D settings > Program Settings > Lost Ark > Vsync > On
Tried reinstalling and changing other graphics settings multiple times, but didn’t help. Other peoples’ mileage may of course vary.