Security check not started

[foobar101118]

Hi everyone - I have applied inland for my PR through Family Sponsorship as Common Law, back in July 2020. My application is still "in progress", with only the security/background check remaining. I received AIP back in July 2021, but since then there hasn't been any update.
I'm wondering if anyone else has been in a similar position, or might have any insights as to why the security check is taking so long.

My timeline is as follows:
- July 27th 2020 - application received
- March 13th 2021 - AOR
- March 15th 2021 - biometrics instruction letter
- March 17th 2021 - completed biometrics
- April 6th 2021 - medicals requested
- April 17th 2021 - medicals completed
- July 14th 2021 - Sponsor approval and principal applicant eligibility updated to passed (AIP), criminality passed

The assessments section in my GCMS notes looks like this:

There's only one entry under the Security section, created & updated on July 14th 2021, with status of "Not Started".

I have also contacted my MP and they couldn't get any more information than this, i.e. that only security remains.

I would really appreciate any insights or suggestion anyone might have! Thank you all!