typedef struct
{
    fp32 x;
    fp32 y;
    fp32 z;
//    unsigned char health_flag         :1;
//    unsigned char feedback_sensor_id  :4;
//    unsigned char reserve             :3;
}api_vel_data_t;

I had to comment out the last three values to fix this issue. I think N1 controller is not outputting this format leading to corruption of all the data that follows it like the global/local position, RC etc.

Please provide this information and contact dev@dji.com.