Whenever i talk to a merchant NPC who also has other chat options than the bartering option, I will get all the correct chat options the first time I talk to him/her. However, when I talk to them again, I get thrown directly into barter mode, and when I go out of it, I see no options besides the trade one. The NPC will now only go directly into trade mode with me, and will not display any other chat options, thus leaving me unable to complete certain quests.

Does anyone have any idea what could be causing this?