This sounds like it might be either that they sent the P2 mail to the lawyer again, despite your instruction to use the direct mail, or (more likely) that this is a technical problem.
In my case I got one email with my (Principal Applicant) name on the top, titled "
PR Portal (PR confirmation) - New Credentials for the PR Portal". Then each of my dependents got another email (at the
same main email address) titled "
PR Portal (PR confirmation) - New Case Created Under Your Account". Which of these subject lines was on the email your dependent got?
In any case, I would suggest to reply to the P1 email address (probably
ircc.clientportal-portailclient.ircc@cic.gc.ca) to report the problem. You can tell them that you cannot access your portal (never received credentials, or case not linked to the credentials), and provide the UCI of yourself and your dependent, and the PR application number. Hopefully the officer can re-generate the P2 mail for you. Or you can try to use a webform to report the problem.