Depends on when you graduated, and when you applied for the PGWP (exact dates).
IRCC changed the language on their website in 2016 to suggest that you must apply for the PGWP before you graduate, to be able to work legally while waiting for the application to be processed.
In the past, you officially had 3 months post-graduation where you were allowed to remain in Canada and work. Most people also applied for their PGWP in this period.
Now, your study permit officially expires on the day you cease to be a student (e.g. graduation day) - regardless of the expiry date on the permit. So I suppose that is the reason why they also had to change the rules for working after graduation.
HOWEVER - the rules that were in effect at the time you graduated are the rules that apply to you.