To get 3D orientation from the paired beacons via the modem, enable the 'IMU via modem' option as shown below:
This mobile beacon should be the left beacon of the pair and have a higher address than the right beacon.
For example, if your paired beacons have addresses 10 and 11, beacon 11 should be the left one, and the 'IMU via modem' option should be enabled for beacon 11.
Examples of reading the streaming data: