accel timestamp inaccurate in FIT file

Hi, I saved accel/gyro/mag into a fit file by using code below

_logger = new SensorLogging.SensorLogger({:accelerometer => {:enabled => true}, :gyroscope => {:enabled => true}});
session = ActivityRecording.createSession({:name=>"test", :sport=>ActivityRecording.SPORT_RUNNING, :sensorLogger=>_logger});
The "gyroscope_data" and "magnetometer_data" are saved with correct timestamp, timestamp_ms, sample_time_offset.
However, the "accelemetor_data" is saved with inaccurate timestamp(date) and sample_time_offset(all 0).
my test device in forrunner945 & my friend's Fenix7 and they both have the same issue. and I have reset the forrunner945 and still not work.
how can I fix the incorrect timestamp? thx in advance