Activation lock on macbook pro

Hi,

I bought macbook pro 2019 from a person 1,5years ago, he restored it, removed his icloud. I linked it with my icloud and used it for more than a year. I decided to restore it cause it was running slow so I removed my icloud, removed it from find my app and when it boots I get activation lock and when I try to enter my apple ID it says this macbook is linked to a different apple id? I called previous owner and he checked his iclouds and theres no macbook linked. He also said that he bought it from a person, but It was sealed so he was the only owner before me. If my apple ID was linked for 1,5years why it asks for different apple id? Thanks