Not able to get FFT analysis

I want to add filters to my copter since I noticed some vibrations. Most vibrations are below 10m/s/s. I followed all the docs for setting up FFT. When I try to do a FFT analysis in fftui its showing a really low frequency input like 24Hz. I’ve enables In-Flight FFT and also tried to run it through MavProxy but it outputs “extracted 0 fft data sets”. Are there any params I am missing or have set incorrectly? This is a fairly large multicopter with 18" props.
I attached my PARAM file.

42 12-31-1979 6-00-00 PM.bin.log.param (18.3 KB)

I’m also in the same situation as you,
although I have read the ardupailot wiki several times I do not know how to do several steps to find the values that need to activate the notch filter … get the FFT… how to determine the frequency to be taken as a reference etcc …
It would take some practical examples and described step by step on how to perform them … so that everyone can proceed on their own without always being asking …