Note: I am not the one you asked this question
You get a COPR document after submitting a declaration that You are in Canada. Once you get COPR, you should ideally wait for PR card because you cannot travel without it. and in the background, once you get COPR - your other visas are cancelled. It is important to make sure you are in Canada while all of this happening.
My friend was waiting for COPR after submitting the declaration and decided to travel. They had no issues while leaving the country, only when they were trying to re-enter