"MY MOTHER APPLIED FOR P.R. IN 2002, GOT IT IN 2004 AND I WAS DEPENDENT. AFTER 5 MONTHS OF LIVING IN CANADA WE RETURNED BACK TO INDIA ON 18/1/2005 OWING TO POOR HEALTH OF MY FATHER."
These were the exact words I used when I applied for my study permit. And yes the UCI number was the same in 2004 and 2018.
Bottom line is that you did disclose.
The pathway of applying for another PR to be honest does not seem very appetizing. As it would involve me waiting a few months to get the PR and then waiting 2 years to apply for citizenship.
I don't blame you for going the route of continuing ('toughing it out'). I do feel bound to warn that we dont' really have any idea how long it may take them to work out the current PR/citizenship - could be quick, could be longer. Unfortunately - as you've found out - it's the unusual cases that can tend to get hung up for what can seem an eternity.
Continuing your current PR app (CEC) after renouncing potentially has the prospect of being quicker for PR status.
But these are only guesses. Good luck and let others know.
[And I haven't begun to touch on work etc. My reading is you're allowed to work, period - IRCC confirmed you are a PR in Canada, after all.]
