This has happened a few times in the game. This one was especially notable because it happened with three companions at once toward the end game, where I would expect new dialogue to pop up.
Companions will get the speech bubble, suggesting they have new dialogue/want to talk to you about something, but when you click on it or talk to them, you only see the preexisting dialogue choices.
In this case, I:
Arrived at Ukaizo, exhausted dialogue with the Guardian of Ukaizo, defeated him, then went to Grand Promenade. When I got there, Xoti, Eder, and Aloth had speech bubbles pop up, but when I talked to any of them, it only showed dialogue I had already seen.
Imgur link goes to a couple pictures showing the issue:
I have attached the system specs from dxdiag.exe, the output log, and what should be a save from right after I beat the Guardian of Ukaizo - in the harbor. If you go to Grand Promenade after you load the file, this issue should happen for you too.
I had to compress it in to a zip file and put it on Dropbox because of the total size. Please let me know if there's any issue with opening/extracting them! Or if I'm supposed to do something else.