Tourism visa issued beyond the expiry date of passport, valid or not

[daijia]

As we know, Canada basically does not issue a TRV that goes past the passport expiry date.

However, back in 2017, when Canada began issuing multi-year visas for my country, I received a visa that goes 4 years beyond my passport expiry date.

Later, when I changed my passport and applied for my study permit in 2019, I received a new visa, I was never informed that the previous is cancelled.
I have also entered Canada on that visa previously for tourism (Before moving to Canada for study), and not once have they mentioned anything.

Now that my current S-1 visa will expire soon, I am uncertain if I will be able to travel on my previous visa, which is valid but on my old passport. Does anyone have any idea ? (I am thinking of leaving Canada for a while - for travel - but applying for a new visa takes time)

Thanks!