Had the exact same problem. Not sure how your factory is set up, but mine has different rooms for each type of meth. What worked for me was to combine the drying rack rooms for cloudy and crystal, add them to both cloudy and crystal room groups, and completely demolish and rebuild the processing room and re-add it to the cloudy room group. Hope that makes sense. But basically play around with the different rooms and room groups and eventually they'll get off of their butts.