I cannot enter the portal in Blacksap's Hold after I have retrieved the sons. I watched other players around me walk back and forth as well. I have included a picture to show there is no interaction cue that allows you to progress.
Happening for me to. Not to fussed about meeting my first bugged quest funnily, I know it'll get patched either Friday or Tuesday (EU)... But my main question is, is there somewhere we can go to see him, or do we have to go through the portal?