when you change your box, recordings are not transferred to the new box.
If your old box has not been desactivated, you can still connect it to the TV without connecting videotron... and you should still have access to your recordings for a period of 30 days.
That actually sounds like a multiroom issue. We may need to manually activate the multiroom service in the new box for it to "see" the PVR (other box in another room). Tech support can do that relatively quickly! You can get in touch with us by phone and chat: http://www.videotron.com/residential/contact-us