Hello,
Thank you for sent files, I see the straight line on your map, but it would be very helpful to have records from that period when issue happened. Your device firmware is 03.25.14.Rev.03, please update your device with the current firmware (03.25.15.Rev.32), I also recommend to set Movement Start Delay to 3 sec, to have accelerometer more sensitive (System->Accelerometer Delay Settings->Movement Start Delay). Please apply firmware update and settings and test device.
Waiting for feedback from you.
Regards