When the management company arranged to have a contractor investigate the chimney in 2014, they found out that the problem is structural. The flue is set about 4-6 inches further back than where it needs to be. When a fire is lit, it hits the top of the opening but as the flue is too far back, the smoke is going back into the apartment.
To solve this issue they put in a stove under their costs. I had someone out to clean chimney pre-Christmas and they wouldn’t touch it as they said the stove was not sealed and it was not installed correctly.