Tiltrotor bicopter FC transition problems lead to crash

Issue with Bicopter in Qstab and Qacro Modes:

Video showcasing the problem: https://youtu.be/jCW-90Thx5k

When operating my bicopter in Qstab or Qacro modes, the system stabilizes with a nose-down attitude by tilting the motors backward. However, it does not tilt the motors forward, regardless of the flight situation, and thus it crashes. Right after recording the last video of the problem, it flipped over completely and broke a prop.

Transition to ACRO Mode:
The transition to ACRO mode functions properly, and the motors operate as expected during this phase. However, in Q-stab, hover, or acro modes, the motors fail to tilt forward as they should.

Motor Tilt Trimming:
I have ensured that the motors are trimmed correctly. In Q-stab, the motors are aligned vertically, while in normal ACRO mode, they tilt forward, which is functioning as intended.

Motor Limits:
The correct limits for motor tilting are set, yet I cannot find a method to allow or instruct the motors to also tilt forward.

Center of Gravity (CG) Adjustments:
I have experimented with various CG placements: nose-heavy, neutral, and tail-heavy. When slightly tail-heavy, the system managed to hover for approximately 2 seconds, but then exhibited the same behavior of not tilting forward.

I am using QGroundControl, arduplane, SpeedyBee F405 Wing, last 4s of video shows the base setup with old motors and cables and other things not done, on the video it’s got better motors and escs, cables tied up a bit too.

Post a log file. We are no diviners.

I was not so bright till I got a first reply here, so I didn’t even put in an SD card. Not by my workshop today, but I will put one in and post the log as soon as possible.

Thank you in advance guys!

Hey guys, finally got to recording and uploading logs. I need to hurry, as the competition I’m building this for is closing in fast on me.

If you can, could you please review these logs?

https://drive.google.com/drive/folders/1eYddFytMBv916Cm6DlLUZ0Td7x2A1PQ-?usp=sharing

Thanks to all in advance.