Does the Oudie 2 have a baro altitude sensor?
I had my Nano connected to the Oudie and supported by an external battery source. The battery failed, the Oudie reported primary gps data lost and reverted to the internal gps for the rest of the flight.

Post mission I compared the Nano log to the Oudie log and noted the baro altitude in the Oudie file went flat about the time of the battery failure, but it had a good gps altitude trace. The Nano had both baro and gps altitude data.

This leads me to think that the Oudie 2 does not have a baro sensor and was recording the Nano data before the failure.

My next flight I connected the Nano USB to Oudie RJ45 supported by ships (aircraft) power. No problems.

Paul, the 11,500 mAhr battery I bought at the SSA Convention failed on its second flight. I cannot charge it or get any power out of it. Glad I had manufactured a Y power cable to support the USB to RJ45 interface.

BillT