Try different ESCs, that would be my next step.
Also check this guidance for wiring:
This looks less like a pure rate-tuning issue and more like a propulsion / ESC / signal integrity problem that later appears as oscillation.
The key point for me is that the aircraft can fly normally at first, then after around 10 minutes the motor noise changes and aggressive oscillations start. That timing pattern makes me think about ESC heating, ESC desync, power/signal noise, or grounding/coupling issues more than normal PID tuning.
The CG offset you mentioned does not look large enough by itself to explain this kind of behavior. A small CG shift can bias motor outputs, but it normally should not create sudden abnormal motor noise followed by aggressive oscillation if the propulsion system is healthy.
A few things I would check before continuing tuning:
• Test with different ESCs if possible
• Check ESC temperature immediately after landing
• Verify motor timing / PWM protocol / ESC firmware compatibility
• Confirm signal ground integrity between FC, ESCs, and PDB
• Keep ESC signal wires away from high-current battery/motor wires
• Check for motor bearing or prop imbalance under load
• Review logs for motor output saturation, current spikes, and vibration clipping around the exact moment the noise starts
• Temporarily reduce payload / reduce current loading and see if the event still appears after 10 minutes
The notch filter and vibration setup are important, but if an ESC is losing sync or becoming unstable under heat/current load, filtering will only mask part of the symptom and will not remove the root cause.
I would also agree with trying another ESC set as the next clean isolation step.
Dr. Fares Al Dhaheri
Al-Etihad Industrials, UAE