Good-day ; Did you receive your PR after claiming refugee status ? If so then I wouldn't advise to use your country passport for travel or anything , I would highly recommend you use a refugee travel document for anything travel until you become a citizen, I know people sometimes get away with it "occasionally" but the reason they have a RTD is for this purpose, not to reavail yourself to the country you claimed assylum from.in the first place. If your passport was seized as your post suggests then you claimed refugee status , I would use a refugee travel document which is now valid for 5 yrs since you're a PR.
You can submit an IRCC webform and select “Update or ask about your application” → “Other.” Explain that you have now become a permanent resident and would like your original passport returned. IRCC will forward the request to the office holding the passport, and they will advise you about the next steps.