If you run a fan with door shut and sealed, it won't do any good. It won't circulate air and it won't remove humidity. In order for the fan to move air, there has to be an incoming flow of air. Otherwise, it will do absolutely nothing unless you have a vacuum pump for exhaust fan.... Plus, air circulation also means dust circulation.
I had few issues with sleeves but both were my fault. One, my film wasn't completely dry. I found out, feeling dry to touch isn't good enough. It takes over night drying and some before it is dry and emulsions hardens as a result. Also, I had to make sure the film was clean and free of dust particles. Otherwise, it just drags across the film.