There are three odometers on the ECMs:
Normal odometer
High resolution odometer
Dashboard Odometer
Mondo ELD HOS uses the High-Resolution odometer, not the one on the dash, as it does not always come on the bus.
Also, in the case of light vehicles (OBDII), the data is sometimes encrypted, and the dongle manufacturers do not pay for the decoding.
The important thing is to see the distance traveled, for the ELD, to verify if when the truck moves, it is seen in the odometer reading.