Start Disavowed. As soon as it starts, you'll be in the command center with the eternally-hanging chat bubble.
Hit ESCAPE to get out of that.
Immediately turn around and go to the elevator leading out of the command center (back up to outdoors Odessen). Take the elevator up to the first floor.
While unmounted, run out... right before you get to the green instance boundary with the outside, it SHOULD launch you back into Disavowed... and at that time you should be able to continue with the actual Disavowed start up cutscene!
I have made this work on two characters so make sure you pay attention to the instructions above to the letter. Good luck!