It may continuously supply water to the macerator even when nobody flushes. That is different from unexplained motor operation with no known inflow.
What the observation means
The toilet cistern mechanism and the pump are separate components. A normal-looking bowl level does not prove that water has stopped entering.
A useful next step
Record the trickle without repeatedly flushing. Arrange appropriate assessment of the feed and unit as needed. If the macerator is failing or overflowing, stop further use and follow safe advice on the water supply; do not open the pump or alter its internal switch.
Manuals and supporting guidance
Model-specific instructions take priority. These references support the practical principles discussed here; they do not diagnose your appliance.