It can show a changing pattern under familiar use. The unit's model and the amount of incoming water are needed to interpret it.
What the observation means
A longer run after a larger fixture discharge is different from a new change after every ordinary flush. There is no universal normal duration for all products and installations.
A useful next step
Use observations already available and report the trend. Stop use if clearance becomes unreliable, running is continuous or other warnings appear. Do not keep timing repeated flushes or assume that a longer run identifies one specific component.
Manuals and supporting guidance
Model-specific instructions take priority. These references support the practical principles discussed here; they do not diagnose your appliance.