[Bug] Crash happened by unexpected ekf instance changed and then sudden manual control loss

[d3637042]

Describe the bug

I was coaching my friend to control my drone using altitude mode but suddenly the drone went out of control and ended up crashing and injured my friend.
I'm using PX4_FMU_V6C with v1.14. I haven't modified this drone for more than a year and it was stable and reliable until yesterday.

So I'm confused about two issues:

1. EKF instance changed which I checked:
   estimator_status/filter_fault_flags: 32768 = 2^15
   # 15 - true if bad delta velocity bias estimates have been detected
   Which innovation test ratio should I look into?

2. I checked the hardware again today and without any fixing, I am able to control it using my RC. Is it possible there is software bug causing MANUAL_CONTROL_LOSS?

To Reproduce

No response

Expected behavior

No response

Screenshot / Media

No response

Flight Log

https://review.px4.io/plot_app?log=88f3c5e5-82ea-459d-9dfc-81a599fd3712

Software Version

v.1.14

Flight controller

Holybro Pixhawk 6C

Vehicle type

Multicopter

How are the different components wired up (including port information)

No response

Additional context

No response

[afwilkin]

It changed because your accelerometer was clipping. Your vibrations are high for the whole flight.

You need to tune your vehicle and ensure the flight controller is isolated from your vehcile vibrations. Or just have it stop vibrating so much. maybe balance props. then after that you can do IMU filtering, and then PID tuning