A temporarily blocked output pipe on a metal refinery causes continuous (or a set amount of) production to cease even after the blockage is cleared.
In the attached save, the metal refinery on the right is setup to reproduce the issue, adding a continuous (or any number greater than 2) order of steel will cause the output to be blocked by the first production and once the output clears the machine will not be manned again until after it clears. If the output is connected to the second sieve (far left), the issue does not appear as output is never blocked.
Build a metal refinery and use polluted water as coolant, have the output run into a single water sieve. As soon as the output backs up because of sieve throughput dupes will stop working the machine (as they should). Once the sieve has worked through the coolant the dupes won't resume production until the production order is reset to 0 and back to what it was.