My situation is similar.
AOR Feb 2020. I also had an ADR in December last year, and submitted the requested docs on Dec 13. Probably this timing was quite unlucky, because it was right before the holiday season.
![Confused :confused: :confused:](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
And by the time when IRCC folks got back from the holidays around January 6-7, my application again ended up in the middle of the stack.
I finally managed to reach the IRCC call center today, and they confirmed that the Security check hasn't been started yet because "every application is different and bla bla bla"