So the first time I played it I had the bug too....the waves of soldiers attacked and It did not trigger the conversation. I logged out and back on, but this time I crossed the bridge which triggered some dialog from Arcann, (that did not happen the first time). After the waves of soldiers it triggered the dialog. Hope this helps some one... So the only thing I did different is go across the bridge right before vette instead of going around it.

Sage, yes I was in the mission before (after you meet back up with Senya)

Yeah i thought I was the only one..Kaliyo hates me....

Also if you make a Lightside/Darkside choice by accident, you can hit ESC to get out of the conversation then start it over again.