Landing detector

Hi everyone,
I was flying my Co-axial Octocopter and faced an altitude issue in which it drops height without any input signal. And when it lands it does not disarms immediately. I have checked its vehicle land detector topic and it senses vertical movement on ground.
Here is the log file:

I have a couple of suggestions you should try first and see if that doesn’t help. It seems like your drone is really badly tuned, you should lower your rate controllers. There also seems to be quite a bit of vibration which might affect the sensors. I think the best cause of action would be to fix those problems first and see if that helps.

Thanks for the suggestions.
Can you please elaborate on which gains needs to be depreciating? Is it K, I or D values?

@bresch Can you please have a look at this?

Try to decrease the P and D values. You can follow this guide.

I have tried but it does not help

Can you send a flight log of a flight after you have tuned to controller?