After completing the cycle, the progress bar on the module (miner or harvester) to stop appearing.
Most commonly occurs after reloading (miner or harvester) charges, and the module continues to work because the field (or plant) is not exhausted.
It does not happen with all the modules, but only with some (randomly).
It looks as if the module is disabled, but counter charge be reduced after each cycle.
It's confusing because you do not know whether the module is on or off.
The problem disappears after I click on the module. But when I clicked on the module, I shut it, so I have to re-start.