One possibility would be the unit was started at a low water level, 1 min 48 seconds equals only about 1/3rd gallon. If you start it with the float raised or nearly raised it should then work.
Another possibility is that with the winter weather, heaters running, etc, the evaporation is very high, the 3 min setting will then solve it.
The last possibility is a faulty pump, a faulty pump will generally not run more than 30 seconds before it shuts down as it triggers an overload safety.