We are in exactly the same situation - my dad's card was mailed but only afterward we noticed that the address on profile is missing the unit number completely (the address on the application was fine - I have a paper copy of my application). Unfortunately I only noticed that 2 weeks after the card was mailed (when I was already wondering why it has not arrived yet).
I phoned IRCC to get the address updated (and the agent did that) but they also said I have to wait 6 weeks and contact them after that (possibly fill out the solemn declaration form that the card was never received, but this can only be done after 6 weeks they said).
Not sure if there is any hope that maybe Canada post returns the card to them and maybe they remail it to us again without me doing any addional steps (that would be a miracle!) - not sure if IRCC will do it without my call or some additional steps (like that form they mentioned).