this is for AG317; CIC states the following:
Situation 1. Accompanying a Canadian citizen outside Canada
You may count each day that you accompanied a Canadian citizen outside Canada provided that the person you accompanied is your spouse, common-law partner or parent (if you are a child under 19 years of age).
Evidence required
You must provide supporting documents to prove that:
The person you are accompanying is a Canadian citizen; and
You are the spouse, common-law partner or child of that person.
So, if your sponsor is a permanent resident outside of canada, and the sponosored person aswell; then it is correct, you loose the PR; if you are a Canadian Citizen living with your partner, who has PR, it's like living in Canada, as is my (i being the Canadian Citizen) and my partner being the PR holder; no issues here.