Ongoing smoke issue

Hey everyone, I need some advice. Ever since February my downstairs neighbor been smoking and my unit is full of smoke.

Some relevant information I am on a top floor of a 3 story building. In 2024 new small size company bought our building and started renovations. 11 out of 14 apartments were brought out of their lease, we were one of those who stayed. So they did a massive renovation, I am taking replacing old bathtubs in the bathrooms, adding new ceiling light fixtures and so on.

Now the issue, they added a fans in the renovated bathrooms, we only had windows before no fans like my appartement still does. But there is no exhaust pipes leading outside from those units so I assume the ventilation is leading to a main shaft and to the roof. The problem is my neighbors are smoking in the bathroom with the fan on and my appartement gets full of smoke and smells terrible. To the point that my smoke alarm is triggered multiple times a day. My theory is because there is no vents leading outside when they turn on fans it pull clean air from the shaft a.k.a my unit and that creates a negative pressure. My unit is not renovated and shaft is not sealed so all this contaminated air just spreads in my unit.

I don't have any other explanation for the smell of cigarettes and visible smoke that coming to my room as a shaft door is in my closet. It's either this or she smokes the whole pack of cigarettes at once.

We have a non smoking unit, and I have reported this to my landlord gazillion times. All they told me is they spoke to the neighbors. Now I have videos of smoke alarm going off and time stamps.

Is there anything I can do beyond just going to the TAL? This has to be some kind of fire safety violation because what if there is an actual fire and fan is in? Will that just pull all that smoke to my unit? Thank you everyone for your advice