recently one of our T40s started flying sideways when starting a route. Its also notacable when departing the takeoff point and heading to its start point. It will turn about 45 degrees to the left but continue straight forward. This is most prominent when it is beginning a route. There are sometimes when it turns almost 90 degrees to the left but continues to fly straight. Something is obviously wrong. Even when I take control, it is doing this sideways thing. I will go full stick forward and it will start flying in the wrong direction, its actually difficult to control, however it still flies okay with no warnings. We have calibrated the IMU, compass, it is on the latest version of firmware.. nothing is different from our 3 other T40s. What else could we attempt in order to diagnose this strange sideways flying issue?

I'm having the same issue.  No errors on the control.  Mine will continue into a roll and will need to land.  It appears to be if I go over 32L or 70#'s things start to have problems.

Looking for answers or any advice to fix.

Is this an automatic flight using TERRA? TERRa V4. There was a bug like this in the version, so it was resolved by changing to V3. Currently, the same symptom occurs in the latest version of TERRA and the latest firmware for T16, T10, T30, and T20p.

I'm having the same issue.  Anything over 32L, the drone will go into a roll.  No errors.  Lower than that it will fly all day, with no problems.

Looking for answers, i'm running the latest firmware.