OctaQuad VTOL massive pitch, roll, and yawing problems

Hi All,

We have built a big Fixed wing VTOL with octaquad setup.This is a huge 3.5 m wingspan 40 kg MTOW aircraft. I have been having problems with the aircraft being highly unstable in pitch and roll. I am having to fight it a lot and even then it doesn’t work. Another issue that is constantly there is the aircraft keep going backwards as if there is a constant pitch up motion. The CG is balanced in fact i even intentionally made the CG towards the front of the fuselage and made the nose heavier and still the aircraft keeps going backwards. Another major issue was the right yawing (toilet bowel flush type). which may have been due to wrong motor sequence but last night i did a bit of work on that and today i did try to fly. But i cant quite say that yawing motion has gone or not. Maybe logs can confirm. BTW, i have flown it it both QStablize and Qhover.

So if someone can look at the logs and help me with three main issues:

1.the roll and pitch instability
2. as well as finding our why the aircraft keeps going back
3. and finally, if the aircraft still trying to yaw right or not. or has this been fixed (i may have fixed it after making the motor spin sequence right last night) For reference i am also sharing previous logs as well of the flight tests before the motor spin sequence change that i did last night. In there you will notice a pretty huge Yaw split.

I am attaching the logs as well as the param file. 020923 logs (one flight being Qstab and other being Qhover) correspond to after fix. and 290823 files is for reference showing pre fix issues.

LINK: 290823-logs.zip - Google Drive, 020923.zip - Google Drive

Your help is deeply appreciated.