This happens often, but is not everytime, usually with npcs I’ve interacted with before for quests. For example the Crusader Johanna in Zarbinzet, once the conversation starts, mouseclicking, escape key, spacebar… none of them work to exit or speed up the conversation. Not a big issue in a town or safe area, but if your party or a player nearby needs help, you are stuck in the conversation unable to help.
I noticed this too, but just alt-tab out and back in and you should be able to end the cutscene/conversation. It’s still annoying and a band-aid solution for now, but it is better than sitting through the whole thing.
Seriously… The correct response for mods here should be “I have moved this post to the proper place. In the future, please post bugs here. Thank you for creating a bug report to fix our game.”