Easement Not Transmitted

Hello, I just bought a house with a garage on the property. When I visited with the real estate broker, he told me that the garage was rented to someone but he didn't know more than that. (The garage is quite big, but old. It has a 4-wheeler and a snowblower and the rest of the space is filled with useless things) Before going to the notary, I met the person who "rented" the garage and this gentleman explained to me that the garage space was his and that it was all his things. So I asked him how much he paid to rent the garage and he told me that he didn't pay anything because it's the previous owner. He explained to me that he made an agreement with the owner to use the garage as long as he wanted until his death. I found it strange so when I went to the notary to take possession of the housing, I asked the owner and the notary if he had any mentions or information about this gentleman and his access to the garage. They told me that he was not right and that it was indeed my garage and that it was not rented to anyone. A week later the gentleman invites me to his home to show me official and notarized documents that as long as he is alive he has access to the garage. These documents are signed by all parties including my seller.

Did my notary do his job wrong?

Did my seller hide this from me?

What do I do?