I'm on the Android version of kittens. When I open the tab for steam works, there is a little button labeled A, and when I tap it, it turns into *, which turns back into A when taped, and so on. This is distinct from the on off switch as coal is still being burned and manuscripts are still being produced.
As a side note, it doesn't seem like beams or slabs are being produced offline (or at all). It worked before my previous reset so I am wondering if it is related.
Best Answer
The A means Workshop automation is active, the * means it's off (workshop automation automatically converts wood, minerals and iron to beams, slabs and plates, once or twice a year when those resources are close to the limit). you may want to turn automation off, when you want to buy something, which is priced very close to your resource cap.