I believe you have to reach out to the MP of your constituency, but let me share a trick that might be helpful. In my case, I believe asking the MP did help. I actually wrote to 2 different MPs, one of my own constituency, and another is of the adjacent one, but happens to be the standing member of the Citizenship and Immigration Committee. For the second one, I said up front that I know my address is not in their constituency, but since the MP is on the immigration committee, I hope they can help take a look.
The first one wrote back a boilerplate response saying that they contacted IRCC but blah blah blah... The second one did call me, leaving a voice mail saying that they called IRCC, who mentioned that my case has been all done, just the portal email left... and a few hours later, I did receive portal #1. The MP office actually called checking the status again a few days later. Of course, we should definitely try leverage any help possible, but it boils down to the luck that whether the MP office really wants to use their direct line with IRCC to help you or not.