AVO doesn't process express entry for Nigerian applicants, they only stamp visas, the applications are processed in London or Canada, they are online applications, and for student applications, most of the applications are processed in Nigeria, especially if online, AVO only stamps the visa.
Unfair, may be, but like I said, Canada puts economic migration before family sponsorship.
Lastly, the timeline is twelve months, these other applications have timelines ranging from weeks to six months, so they always come before us.
All will be well, I am an early April applicant, so I understand your plight.