2/1 on S mesh?
Sounds to me like you probably have a stencil that's too thick to expose anywhere near properly.
Try it out--coat one 1/1, even try a single pass on the shirt side, dry shirt side down.
IMHO, buy a humidifier if you have humidity problems.
A heater in the screen room (NOT a cabinet) works great here, as the RH is almost never over 40%.