Dear friend,
Your PR is on its way, my case was similar my AOR was received on 14th October 2015 and after that BG never started, nor it changed to in progress, additional documents not needed, no ghost E-mail. However in the middle of the night, I just got one e-mail and it said ready for visa, exactly on the 155th day.
Just hope same happens with me. No movement on file since AOR
So going by the trend you should receive it in a couple of weeks and I am guessing that instead of updating the status CIC is just sending the the PRs and closing the files.
All the best and congratulations in advance, c u in Canada
Regards,
Avish