popular words API returning no records

(from github.com/markcamos)
fess version 12.4
config reloader running */10 * * * *

https://fess-devel.owenscorning.com/json/?type=popularword returns:

I’ve been searching for the same term every couple of minutes for days. The search shows up in the search log, but not popular words.

Any ideas on what to check?

(from github.com/marevol)
See https://github.com/codelibs/fess/issues/1813#issuecomment-458126751

(from github.com/markcamos)
There is nothing in 1813 that I haven’t already tried.

I think we just won’t be using this feature.