Got my TRV passport request before getting PGWP

So I applied for a PGWP but it's still under process and I applied for a TRV after leaving Canada on an Implied status and the TRV got approved a few days back. Kinda unique situation but I'm a little confused. Can I travel back to Canada and continue working with my Work-Permit EXT form as my job while my post-grad work permit is under process? Also what would I have to tell the immigration officer at the airport for reason for stay (if they ask)?