For the ignition source, it is better to use the DIN 1, and directly connect the DIN 1 to the vehicle ignition.
The problem with the voltage source is that when the voltage value is incorrect it will not work properly for example you set the min voltage to 14 V and the high voltage to 30 v.
Then the vehicle starts and the voltage increase from 12V to 13V it didn't reach 14 V which means the status of the ignition is still OFF because the voltage didn't reach the minimum value which is 14 V, using voltage as a source make sure that you measure the change of voltage when the ignition is off and when the ignition is ON to have an accurate result.
You use an accelerometer as a source which means if any movement from the accelerometer is detected the ignition is ON. In ECO driving ignition status is important.
Kindly try DIN 1 as a source and let us know the result.
Reference: FMC640 Features settings - Wiki Knowledge Base | Teltonika GPS (teltonika-gps.com)
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