I think its because you have the magnetic on/off switch between the sensor and the battery. See the manual drawings here.
You must have a on/off switch before the current sensor and receiver. Not between sensor and receiver as you have
The upper exampel says no to a switch between receiver and sensor.
The magnetic switch is only a day switch, I mean when you put your aircraft away that day you must disconnect batteries. The LED light in the magnetic switch will draw your batteries empty over time.